The endgame of the current Parliamentary year is fast approaching.
The key entries on the Commons agenda are now those for consideration of Lords amendments to an impressive array of government bills which have been mangled by peers.
After a week which saw six government defeats in the Upper House, with the potential for plenty more, expect the fabled Parliamentary ping-pong, which sees bills bouncing back and forth between the Lords and Commons to dominate events.
Ministers will want to overturn Lords amendments to the Immigration Bill, the Trade Union Bill, the Housing and Planning Bill, the Enterprise Bill and the Energy Bill, or at least negotiate compromises. And the clock is now ticking.
As usual, the date for the prorogation of Parliament is left unspecified, but the State Opening, which signals the start of the 2016-17 session, is now inked into the Royal diary for 18 May - which means there's about a month left to get the outstanding legislation through its remaining stages of consideration and any disagreements between the two Houses reconciled.
That's not impossible, but the government could find itself having to make concessions to buy off opposition on issues where peers are disinclined to surrender to the will of the Commons, because if a bill is not passed when time runs out, it falls.
Imagine a Victorian-gothic High Noon, involving people in knee breeches, snatches of Norman French, parliamentarians sitting through the night, and increasingly tetchy negotiations in panelled offices, and you begin to get the picture. But with big issues to be resolved, it's a very high-stakes game. So aside from the outcome of actual votes in the Lords, watch how long the debates take - because the time factor becomes increasingly crucial at this time of year.
Here's my rundown of the week ahead.
The Commons opens (2.30pm) with Defence questions - and that is followed by Backbench Business Committee debates. First Labour's Siobhain McDonagh raises the introduction of the National Living Wage and related changes to employee contracts - she is worried that some employers are cutting overall remuneration packages to offset the cost of its introduction, leaving thousands of low-paid employees significantly worse off.
She has already highlighted the case of workers being forced to sign new contracts with cuts in Sunday and bank holiday pay, bonuses abolished, and London weighting hugely cut.
The second debate, on educational attainment in Yorkshire and the Humber is led by Labour's Jo Cox, Conservative Martin Vickers and the Lib Dem, Greg Mulholland. The motion calls for the government to address the underlying reasons for the under-performance in the region.
The adjournment debate, led by Labour MP Jim Fitzpatrick, is on the Metropolitan Police Special Enquiry Team investigation into electoral fraud in Tower Hamlets. Last year, the Election Court voided the election of Lutfur Rahman as Mayor of Tower Hamlets in 2014, and barred him from standing for public office for five years.
Mr Fitzpatrick is concerned that the police and the Crown Prosecution Service now say they will be taking no further action in this case. He says the people who challenged the election are owed their costs.
In Westminster Hall (4.30pm) MPs will debate E-petition 105660 on funding for research into brain tumours.
In the Lords (2.30pm), questions to ministers cover additional runway capacity at London's airports, the extent to which general road traffic laws are enforced on cyclists, and the effect of EU withdrawal on the UK tourism and hospitality industries.
Then, peers continue with the report stage of the Housing and Planning Bill - where the key issues are concerned with "pay to stay" and secure tenancies. Having taken some stinging defeats, Labour sources say the government now realises it needs to make concessions on the detail of the bill - so it is not yet clear whether they plan to force any of their amendments to a vote.
The Commons sits at 11.30am for Treasury questions, after which the Conservative Anne Main will present a ten minute rule bill to require farm produce to be labelled to show its country of origin and whether it meets animal welfare standards.
The day's main legislating is on the Bank of England and Financial Services Bill (report and third reading). The bill makes a series of detailed technical changes to the internal governance and oversight of the Bank, its senior managers' regulatory regime, pensions guidance and advice; and the rules on bank notes issued by banks in Scotland and Northern Ireland.
The adjournment debate, led by the Conservative Robert Jenrick, is on the treatment of UK citizens returning from fighting against so-called Islamic State, or Daesh/ISIL - he believes hundreds of UK citizens have volunteered to fight with Kurdish forces against IS, or Daesh, including some vulnerable people and many are ex-servicemen, and he is concerned that the government appears to have no policy on how it regards them. Should they be seen as allies or are they suspected terrorists? Mr Jenrick has a constituent, Aidan Aslin of Newark, who was arrested on his return and spent weeks waiting to see if he would be charged with any offence.
In Westminster Hall, the day's debates cover unaccompanied children (9.30am); children's homes (2.30pm) and regional variations in the rate of teenage pregnancy (4.30pm).
In the Lords, peers will be dealing with the latest round of Commons amendments to the Enterprise Bill - where ministers have now accepted Labour's amendment which asks the pubs code adjudicator to ensure PubCos do not "game" the code. They have now deleted the Lib Dem peer, Lord Teverson's Green Investment Bank amendment, but have implemented it in practice by creating a special share structure that maintains the bank's focus on environmental issues.
After that the House moves to day two of report stage consideration of the Trade Union Bill, where a series of issues are likely to be pushed to a vote.
There's an amendment on retaining the "check-off" system allowing payroll deduction of union subscriptions, on the powers of the Certification Officer for Trade Unions, and the implementation date for the facility time and check-off clauses of the bill.
The Commons meets at 11.30am for Northern Ireland questions, followed by Prime Minister's questions, at noon.
Next comes a Ten Minute Rule Bill on Forensic Linguistics (Standards) - from the SNP MP Roger Mullin. He wants to bring in a professional register to guarantee the standards of practitioners of a new discipline that can, for example, identify that an apparently innocuous conversation online is, in fact, aimed at sexual grooming of young people or terrorist recruitment.
Evidence from forensic linguists is accepted in American and other foreign courts, but not in the UK - although it is used in law enforcement. A register would help the courts to accept evidence of properly-qualified specialists, Mr Mullen argues.
After that, it's ping-pong time - as MPs react to Lords amendments to the Energy Bill - the government has lost several votes in the Lords on onshore wind generating stations and the remit of the new Oil and Gas Authority.
Then there are two debates chosen by the Backbench Business Committee, on recognition of genocide by Daesh (IS) against Yazidis, Christians and other ethnic and religious minorities and on record copies of Acts - this is a move to overturn the decision to abandon the centuries-old practice of printing acts of parliament on vellum, scraped goat's skin.
Vellum is known to last for centuries, and the parliamentary archives included original documents personally signed by Tudor monarchs. There was a move to save money by switching to printing them on special archive paper, but the break with tradition has met strong opposition in the Commons - and the House authorities are not planning to resist it, after government ministers announced they would meet the cost of continuing to use vellum.
In Westminster Hall, there are debates led by backbench MPs on the effect of aircraft noise on local communities (9.30am); the future of the Cardiff coal exchange (11am); the UK dairy sector (2.30pm); government policy on the trade in small weapons (4pm) and Western Sahara and self-determination (4.30pm).
In the Lords. the day's main legislation is the continuation of the marathon report stage of the Housing and Planning Bill - where peers will focus on the sections dealing with client money protection and local plans.
They may also move onto other planning issues, if time allows. Dinner break business is on progress towards the introduction of the Horseracing Betting Right, the proposal to replace the existing horserace betting levy with a new charge administered directly by the racing industry.
The Commons meets at 9.30am for questions to the Culture, Media and Sport department, the House of Commons Commission (the Commons administrative arm) and questions to the Leader of the House, Chris Grayling. He then remains at the despatch box to deliver the weekly Business Statement on the future agenda of the Commons.
The day's main event will be a debate on "An humble Address to mark the occasion of her Majesty the Queen's 90th Birthday", with the PM and the Leader of the Opposition opening proceedings.
And the Lords begin their day (11am) with a parallel debate on their own Humble Address.
Then, after half an hour of questions to ministers, peers turn to the detail of the Northern Ireland (Stormont Agreement and Implementation Plan) Bill - where the main issues are tackling paramilitarism and balanced budgets.
There will also be a short debate on the report of the Lords Communications Committee on BBC Charter Review: Reith not revolution.
The Commons is not sitting.
The Lords (at 10am) continues its work on private members' bills, rubber-stamping a couple of uncontroversial measures - the Criminal Cases Review Commission (Information) Bill and the Road Traffic Act 1988 (Alcohol Limits) (Amendment) Bill before moving onto the (still not very controversial) House of Commons (Members' Fund) (No.2) Bill.
The main action will be on the committee stage debate on the day's final measure, the Council Tax Valuation Bands Bill, from the Conservative peer, Lord Marlesford who argues that it is "not acceptable in today's world that the most expensive property pays only three times the amount of the humblest and cheapest property", and proposes a series on new valuation bands:
- below £250,000
- between £250,001 and £500,000
- between £500,001 and £1,000,000
- between £1,000,001 and £2,000,000
- between £2,000,001 and £5,000,000
- between £5,000,001 and £10,000,000
- between £10,000,001 and £20,000,000
- over £20,000,000
The valuation would be based on sale price after April 2000 - and homes not sold since that date would keep their old council tax valuation.
This is, to put it mildly, a sensitive issue - the Coalition government promised a revaluation of properties for council tax but never actually started the process - and the current valuations date from the 1990s.
But any move to revalue would push up bills and possibly trigger furious protests.