Nick Clegg, David Cameron and House of Lords reform

Hands up if you think reform of the House of Lords should be one of the key priorities for Parliament. Do you want the chance of voting for a Lord by 2015? Anyone?!

If your pulse doesn't exactly race at the thought of yet another attempt by yet another government to reform the Upper House you might think it curious that today the government will take another step towards a battle which could divide the Coalition and bog down Parliament for day after day later this year.

This afternoon Nick Clegg and his Tory deputy on constitutional reform Mark Harper will face a parliamentary committee to discuss the government's plans to reform the Lords - they propose elections in tranches until, eventually, 80% of peers are elected.

Conservatives tend to raise their eyebrows when this subject is raised and remind you that before he became Prime Minister David Cameron joked that this would be a "third term priority". It is, they say, part of the deal with Nick Clegg. The Lib Dem leadership is no more keen, though, to take sole ownership of this and stress it's a shared project - no-one wants to be seen by voters as obsessives more concerned with constitutional reform than the economy or the health service - and it's referred to with a smile in Nick Clegg's office as "the Mark Harper bill".

Clegg and Harper will try today to answer the age-old challenge - if it ain't broke, don't fix it - with a couple of eye-catching calculations. If peers continue to be appointed at the rate they have been and live as long as they are, there could be 1000 of them in ten years - confirming the Lords as the biggest parliamentary chamber in the world.

What's more, the costs of all these peers will soon get serious if, as is happening, more and more turn up to qualify for their daily tax-free £300 allowance. Harper's back-of-the-envelope calculation is that you would have to have a £1 million pension pot to receive that sort of sum in your 60s, 70s and 80s.

The conventional wisdom states that:

- MPs will always resist another elected chamber which challenges the supremacy of the Commons. 70 of the Tory MPs who voted against similar proposals in the last Parliament are still there now

- their Lordships will always resist abolishing themselves

- the public will turn off at the spectacle of so much time being spent on so low a public priority. In other words, the whole project is doomed to fail - again.

However, I am hearing other credible voices who point out that:

- all three main party manifestos backed elections for the Lords

- David Cameron has done a deal with Nick Clegg to deliver this and won't renege for fear that the Lib Dems could still reject the Tories' dreamed-of boundary changes

- the younger generation of Tory MPs are in favour of change

- The public may not care much but polling shows a clear majority of them back change too

This is a story that no-one wants to make headlines but will dominate an awful lot of political time in the months to come.