MIKE Russell has been criticised after comparing leading Tory Brexiteer Jacob Rees-Mogg to an alien.

The Scottish Brexit Secretary said he was sorry “if the joke misfired in any sense”.

He made the comment while giving evidence to Holyrood’s Finance and Constitution Committee.

Mr Russell was asked whether Theresa May’s draft Brexit divorce deal was better than a no-deal Brexit.

The SNP MSP said: “A no deal would be worse than this.

“When it comes to a choice between this or alien invasion, this is better. But the reality of the situation is both are very bad.”

After Scottish Tory shadow finance secretary Murdo Fraser pointed out an alien invasion was somewhat less likely than the UK crashing out of the European Union, Mr Russell shot back: “Oh I don’t know, have you seen Jacob Rees-Mogg?”

Scottish Tory shadow Brexit secretary Adam Tomkins later asked him to withdraw the remark.

He said: “I have my quarrels with Jacob Rees-Mogg too, but describing him in the context of an alien invasion is a remark which – I know it was a rush of blood to the head, Cabinet Secretary, but frankly it was beneath you. Would you like to withdraw it?”

Mr Russell responded: “My blood didn’t rush to my head, but if the joke misfired in any sense then of course I’m sorry about that.”

It comes as Mr Russell defended his assessment of Mrs May’s withdrawal agreement as a “very poor and disastrous deal”.

He was accused of rushing to condemn the document before even reading it, but said his initial assessment had proved correct.

Mr Rees-Mogg is chair of the pro-Brexit European Research Group and a high-profile critic of Mrs May's deal, which he argues would tie the UK to EU rules.

He is one of a number of Tory MPs to publicly push for a no confidence vote in the Prime Minister.

But the MP for North East Somerset has been accused of presiding over a Dad's Army-style rebellion after so far failing to rally enough support to spark a leadership challenge.

He previously joked: "I've always admired Captain Mainwaring."