Further to yesterday’s blog, I’ve spent the afternoon taking the temperature of Labour MPs after their party’s decision to back 100 per cent devolution of income tax to Holyrood. I think it’s fair to say the temperature is at morgue chiller levels.

I have never heard such unremitting gloom from every wing of the Labour Party: front bench, shadow cabinet, backbench, Scottish and English.

The consensus is that this moment marks the beginning of the end of the UK, a slippery slope onto which the party has tripped courtesy of David Cameron/ Gordon Brown/ Lord Smith of Kelvin/ Ed Miliband/ Alex Salmond/ fate depending on who you talk to.

What all the parliamentarians I spoke to agreed on was that 100 per cent income tax devolution was too close to independence itself for their liking, was inherently destabilising to the UK and bound to feed demand for full-blown independence.

Here are a few tasters of the chats to give you a flavour of it:

Shadow cabinet member: “If the Tories win next year that’s it now, it’s [Scotland’s] gone … It is very frightening.”

Labour MP, former minister: “We walked straight into the trap … I don’t see how we win a second referendum.”

Me: “I keep looking for a Scottish Labour MP who doesn’t think this is a complete disaster.”

Scottish Labour MP: “Well you’d better keep looking … I can’t see any point in carrying on with this (job) now.”

Shadow cabinet member: “We had no choice, we were boxed in … But yeah, it could be the end.”

Labour MP: “I don’t see how this doesn’t lead to independence …. I just can’t see it going anywhere else.”

Former Labour whip: “We have been completely and utterly out-manoeuvred.”

The Smith Commission announces its findings tomorrow morning.