Just last week I was boggling at the number of constituencies that are still, four months away from the start of the election campaign, without a candidate.

Now another one has joined the list. Stephen Dorrell has announced he is standing down as Conservative MP for Charnwood. He has held the seat since 1997, and before that represented Loughborough since 1979. His seat is safe Conservative territory and is likely to attract a cartload of hopefuls who have neither the time nor inclination to fight one of the vacant marginals:

As Anoosh Chakelian notes for the New Statesman, Dorrell is the latest in a lengthening line of moderate Tories who are leaving parliament in 2015. His announcement was unexpected and suggests we shouldn’t rule out other surprise departures even closer to polling day.

Meanwhile Labour is facing a selection dilemma of its own in the seat of Cynon Valley.

First Ann Clwyd said she was standing down, then she changed her mind, and now has to face a re-selection contest with three other contenders.

The BBC reports that under Labour party rules a serving MP can be re-selected by a “trigger ballot” if more than 50% of local party members agree to back them. But “sources within the Labour party questioned whether there was sufficient time to organise a trigger ballot… before the general election.”

Another reminder that the clock is ticking – for all parties.