The breakaway former Labour and Tory MPs announce their roles and responsibilities.Read more
The government's facing calls from MPs of all parties to strip Govia Thameslink of its rail franchise after widespread cancellations and delays in Bedfordshire and Hertfordshire following the introduction of new timetables.
Rail minister Jo Johnson told the Commons the disruption was "unacceptable" but that passengers would be compensated.
However the Labour MP for Luton South, Gavin Shuker, says it isn't enough.
He wants people claiming delay-repay compensation to be spared multiple claims to fit in with the company's 28-day policy and to be allowed to put in one claim covering the whole disruption which began 44 days ago.
He asked the minister "to ensure that everyone who had a valid claim since 21 May receives compensation."
Govia Thameslink has announced that from today, first class carriages on Thameslink and Great Northern routes will be declassified during peak times until 15 July when a new interim timetable is introduced.
Trains on the Thameslink and Great Northern network have been subject to delays and cancellations since new timetables were introduced on 20 May, and the training of drivers on the new routes and trains continues.
The decision comes after a letter sent to Secretary for Transport Chris Grayling from several MPs whose constituents have been affected including Gavin Shuker (Labour, Luton South), Bim Afolami, (Conservative, Hitchin & Harpenden) and Alistair Burt (Conservative, North East Bedfordshire).
Mr Burt said he was "delighted" about the "sensible decision".
"Pleased to have at least achieved this small concession for my constituents struggling through this awful disruption," he said.
Transport secretary Chris Grayling is rejecting calls to resign after widespread cancellations and delays on Govia Thameslink railways following the introduction of new timetables.
In the House of Commons, the Conservative MP for Hitchin and Harpenden, Bim Afolami, has said he understood the report would "look at culpability" but "how much more evidence do we need that the senior management of Network Rail and GTR is incompetent, incapable and inept and how long can they go on?".
Also in Parliament, the Conservative MP for Mid-Bedfordshire, Nadine Dorries, demanded any compensation be much bigger than anything suggested so far.
She asked: "Will [the secretary of state] also insist that a compensation scheme is not one month's free rail use... more like six months free rail use on their season tickets once trains are running normally?"
The Labour MP for Luton South, Gavin Shuker, has told the BBC Mr Grayling must take responsibility.
"This is a transport secretary who said sorry many times in the Commons [on Monday] but took no responsibility either over what's happened here or what is going to be done to clear it up," he said.
"I'm afraid making this the problem of the operator and Network Rail ignores the one part of the system which we expect to step in when things go wrong - that's the Department for Transport - that's Chris Grayling."
The minister has ordered an independent inquiry into what he says is "unacceptable disruption" on Thameslink and Great Northern.
"I will not hold back from taking appropriate action if the review finds that there's been negligent behaviour," Mr Grayling added.