The Chilcott Inquiry stands in the way, Brown cannot duck out of appearing at that now (week after next apparantly) without cries of foul being heard. He simply cannot in the middle of a campaign appear for a day in primetime on the news Channels. The logistics of Easter seem to preclude dates up to 15th April. There's the issue of NI Devolution to process before 12th April too.
The Logic still seems to point to 6th May with Parliament being dissolved on the morning of the 12th April following completion of the NI issue.
Realistically the only dates left in the Calendar are 15th, 22nd April and 6th May.
29th April being excluded because of the Bank Holiday on 3rd May and the availability of adequate count staff as a result on 30th, the Friday of a bank holiday weekend. Campaigning over Easter will be messy with some offence inevitably caused if politicing is seen to be done on Good Friday or Easter Sunday, so that raises doubts over the two other April Dates additionally.
Actually, DVB Cornwall, there are two dates
prior
to those you've suggested; 18th March and 25th March.
The Chilcott Inquiry doesn't stand in the way of the election at all. Sir John Chilcott has stated publicly that once Parliament is dissolved, the Inquiry will suspend its sitting until after Polling Day. This would easily resolve the problem of the PM monopolising media coverage during the campaign. There has been no announcement concerning the PM's testimony at the Chilcott Inquiry and the dates in circulation at present (3rd or 4th March) are speculation.
As far as Easter is concerned, that won't pose an issue either - Easter begins on 28th March (Palm Sunday). Given this, Polling Day could quite easily be 25th March. Rather conveniently too, Parliament has yet to rule on when its Easter recess should be
http://www.parliament.uk/what_s_on/recess.cfm. It is possible, therefore, that Polling Day could be 25th March. In such circumstances, it is feasible that Parliament could reconvene on 29th March and sit until Maundy Thursday (1st April) before rising for a long weekend.
I'm not sure how much attention will be directed at the NI situation. There is a strong case for dissolving Parliament and electing new representatives in the Province. There have been rumblings in the last few days that a slight shift in the current political composition in Ulster would result in a political landscape more amenable to the wishes of the Government, vis-à-vis power sharing and police powers. Equally, given how fragile the deal brokered is, an election would (if Labour lost) dump rather unceremoniously the NI issue squarely in the Conservative's lap.
It is entirely possible therefore that with the launch of Labour's election platform and themes tomorrow, Parliament could be dissolved anytime between this Monday and the following Monday. The last possible date for a dissolution (if Polling Day is 25th March) is 1st March. With the polls showing a narrowing of the gap between the Conservatives and Labour (7 points), given that tomorrow is the launch of the election platform, given that the ONS will, in all likelihood, release figures in April showing that the economy has slipped back into recession (a nightmare scenario a week before a May Polling Day), and given that there must, at some point, be tax rises and spending cuts to rein in the public finances and debt, an election on 25th March is likely. And that means a dissolution anytime between now and 1st March.