AN angry Tory MSP has claimed that the Scottish Government's Brexit Bill, designed to protect Holyrood from an attack on devolution by Westminster as the UK leaves the EU, is a "stunt".

Graham Simpson, the list MSP for Central Scotland and convenor of the Delegated Powers and Law Reform Committee, said it was a "farce" and that few people in Scotland even cared about the Bill.

"As a parliamentarian I am furious," he said, adding that "nobody outside the Holyrood bubble is following any of this."

The Greens' Ross Greer was quick to hit back on Twitter. "Irrelevant even if it were true," he wrote. "What's essential and what's widely interesting are often different things. Parliaments cannot ignore the important because it's boring."

MSPs were debating the second stage of the Scottish Government's Continuity Bill, which is being rushed through Holyrood as emergency legislation amid a constitutional crisis between Westminster and Holyrood over powers which are set to return from the EU.

But despite the short turnaround, Scottish Brexit Secretary Mike Russell insisted the Bill would be properly scrutinised.

Russell said while the procedures being put in place for the MSPs to examine the legislation were "unusual", he stressed there was "enough time" for scrutiny.

Russell was speaking ahead of the rare late night meeting of one of Holyrood's committees, with MSPs sitting from 5.45pm to consider the UK Withdrawal from the European Union (Legal Continuity) (Scotland) Bill.

With more than 230 amendments to the Bill lodged, MSPs will have to sit late into the night - with the Parliament also having earmarked more time on Wednesday morning for this if it is needed.

The Scottish Government stating it has to be passed before the UK Government's EU Withdrawal Bill gets final approval. Ministers in both Edinburgh and Cardiff have branded that legislation as being a Westminster "power grab".

Agriculture, fisheries, food labelling and public procurement are among 24 devolved policy areas the Downing Street wants to temporarily retain power over following the UK's exit from the EU, to put in place UK-wide frameworks.

Speaking about the Scottish Government's Bill, Russell said: "I can confirm that as things stand the Government is of the view that it is necessary to proceed with this legislation.

"All along, the objective of the Government, and the Welsh Government has been to reach agreement on amendments to the UK Government's Withdrawal Bill. Sadly we haven't yet reached such an agreement."

The changes that the UK Government has put forward - without the agreement of Holyrood ministers - "unacceptably constrains devolved competence", Russell argued.

He added: "I remain hopeful agreement can be reached, but we're not at that stage and this parliament needs to have a backstop. It needs to have this Bill. I recognise that the procedure for this bill has been unusual.

"But there is enough time for the Bill to be properly scrutinised and that is what will take place."

Conservative MSP Adam Tomkins said the Scottish Government Bill was a "woeful piece of emergency legislation which will do nothing but bring this Parliament into disrepute".

With Holyrood's Presiding Officer having already ruled the Bill to be outside of the Parliament's legislative competence - something contested by the Scottish Government - Tomkins argued "there are a number of provisions that are manifestly and straightforwardly incompatible with the requirements imposed on us in the Scotland Act".

He added: "It's not too late for the SNP to withdraw this Bill - it's bad law, we should abandon it and not enact it."

Scottish Conservatives have tabled the majority of amendments to the Bill, and a spokesman for First Minister Nicola Sturgeon said: "It would appear on the face of it that they have laid down a lot of amendments to take up a lot of time and we will see where deliberations get to this evening."