Rather bleary, I heard a package on the Today programme this morning with James Graham saying that join press conferences, such as yesterday's with Chris Huhne and Barnoness Warsi, were not a great idea. James ruled out a 'Coupon Election'. The issue is hugely important for the short-term future of UK politics. Are we looking at a de-facto merger not just a coalition? Back on 10 July David Cameron told the Mail that he envisaged a form of electoral truce in 2015,

'We have different underlying philosophies and differences in approach and policy. But obviously if we are fighting a separate election after a successful five-year government, I hope we will be relatively polite about each other.' The usual election battle between the parties would be 'rather odd having had a government we could be proud of', he said.

The suggestion of a continuing electoral pact, clearly implicit here (with the possibility of candidates not running against each other in marginal constituencies) should have been politely but firmly shot down by Nick Clegg. It wasn't and this has created a perfect eddy for media speculation to grow around.

Cameron's message could not have been clearer,

'I think if we can succeed we can demonstrate that these two parties can work well together for the good of the country – that I think does reshape politics.'