Andrew Adonis: have you thought about this?

In tomorrow's Observer, Andrew Adonis says

As a member of Labour's team in the coalition negotiations with the Liberal Democrats in May 2010, I might not be the most objective commentator. But what I saw then, and what the country has seen since, has convinced me that Clegg made a series of serious misjudgments which are costing the country (and his party) dear.

First, he closed down his options. By saying that he was obliged to seek agreement with the party that had won the most seats – a mythical constitutional doctrine – he gave legitimacy to the Tories and fatally undermined Labour support for a Lab-Lib coalition. With Labour and the Lib Dems having 315 seats, plus 28 from largely anti-Tory smaller parties, against the Tories' 307, this remained mathematically possible. But Clegg changed the dynamic and turned decisively right, not left.

Now, I've been saying for a while that it will make for 'interesting times' if, after GE 2015, the Tories have the largest number of votes and the Labour Party have the highest number of seats, and we have a commitment to talk first to the 'largest party' about a coalition - then how are we defining 'largest'?

But now we have a member of the Labour negotiating team from the last election telling Nick to keep his options open on how to define 'largest' - when the electoral maths and the current boundaries indicate that even if the Tories close the opinion poll gap - and the momentum seems to be with them - Labour will end up with most seats.

Any observer of Lib Dem internal politics would know there is a wrestling match internally about which way to jump first post 2015. You'd think Adonis would be making the case for seats over votes. But he's not.

What ever was he thinking of?