SNP - no invite to rainbow alliance

"Our plan does not involve the SNP," a senior Labour source tells me."It couldn't be clearer."

Reading the tea leaves from this morning's radio manoeuvres I wasn't holding out any hope anyway of the SNP being involved in the rainbow coalition that Labour and the Lib Dems are trying to lash together.

The SNP negotiation team - Westminster leader Angus Robertson and Stewart Hosie - have been in London since Sunday but so far the phone hasn't rung.

Douglas Alexander, Labour's campaign manager, sent them a pretty clear megaphone message in a radio interview this morning when he said the differences between Labour and the SNP are "too great" to involve the Nats in a coalition.

This is as much a signal to his own west of Scotland Labour MPs - who have a visceral hatred of the SNP - as much as to the body politic. Former Home Secretary John Reid has already said a coalition would be the self-destruct button for both parties and Tom Harris, Glasgow South, has made clear his opposition to PR.

Labour in Scotland has seen its hegemony in Scottish local authorities disappear since the Labour-Lib Dem coalition in the Scottish parliament introduced PR. There are Lib Dem and SNP cooncillors putting scooters on the lawns of Labour MPs all across Scotland and they don't like it. Two reasons there not to like coalitions or PR in elections, say Scottish Labour MPs.

Angus Robertson's smile was as wide as the Moray Firth yesterday when news of Labour-Lib Dem coalition talks came through, but the SNP "negotiator" might have just been happy because of the demise of Gordon Brown.

But while Brown has played a very clever post-election strategy to keep Labour in the game Alex Salmond booted the SNP off the park in the opening minutes.

He blundered by pushing himself forwards as the linchpin of a progressive alliance. In doing so he completely ruled out that the SNP would support the Tories. As Labour see it he has effectively boxed his party into a position where they cannot vote against a Labour-Lib coalition, if that is what comes out of today's talks.

As Paddy Ashdown said on radio this morning, a Labour-Lib Dem minority coalition will simply dare the smaller parties to vote down the government. The last time the SNP did that, in 1979, they had 11 MPs. They returned to Westminster after the election with just two.

"If they want to be part of a progressive alliance, that's great but they will not be part of a formal coalition," says the Labour source. "If they had 20 seats they might be players, but they have less than the DUP."

There is not even the mood in Labour to offer the SNP any kind of face-saving gesture, like the release of the £250m fossil fuel fund from the Treasury without a proportional reduction in the block grant.

There is even a hint from Peter Hain, the Welsh Secretary, that Plaid Cymru can be brought aboard the coalition, so splitting the Celtic alliance. Tomos Livingstone, over a 07.25 to Paddington, will be better informed no doubt, but Hain did nurse the coalition deal between Plaid and Labour in the Welsh Assembly.