Tory Chris Grayling made an excruciating blunder today, when he told Scottish MPs they wouldn't have been allowed to vote on the Scotland Bill under controversial proposals for England and Wales only laws.
Tory plans to introduce "English Votes for English Laws" have been branded "shambolic" after Grayling's embarrassing slip-up.
Under the new rules, to be voted on this week, Scottish MPs would be banned from voting on laws that don't affect Scotland.
Mr Grayling listed 14 bills that Scottish MPs wouldn't have been able to vote on - among them the Scotland Bill.
The Scotland Bill, which became law in 2012, gave the Scottish Parliament the power to set its own levels of income tax.
The Cabinet Office were forced to admit the inclusion of the Scotland Bill had been a "rather unfortunate mistake."
Ms Blackman said: "This is typical of the UK Government's attitude to English Votes on English Laws - it's ham fisted and shambolic.
"Classing the Scotland Bill as England and Wales only would be completely daft- they could have scrutinised this response before sending.
"There are genuine constitutional concerns with this proposal - not least the way it's been implemented. Changing standing orders rather than introducing legislation is clearly an attempt to avoid proper scrutiny."
Scottish MPs are worried the new rules will make them 'second class citizens' in the Commons.
They're also concerned the rules are being rushed through without proper scrutiny from MPs and peers.
The rule will be introduced as a House of Commons standing order, rather than a law - which means it doesn't have to go through the House of Lords
Lib Dem MP Alistair Carmichael triggered an emergency debate on the rules, to be held tomorrow.
He said: "To seek to do this in one day by amendment to our standing orders may be technically competent, but it is still an abuse of process.
"It is constitutionally outrageous and I fear that it puts a further unnecessary strain on the union."