THE author of Article 50 has said Theresa May could fail to secure the legislation required for Brexit and put the country through another election next year.

Former diplomat Lord Kerr of Kinlochard also said the EU Withdrawal Bill, as drafted, appeared to “fly in the face of the devolution settlement”.

The Scottish and Welsh governments say the Bill is a “power grab” which would see devolved powers repatriated to Westminster at Brexit, not Edinburgh or Cardiff.

Lord Kerr said the “fundamentally important” concept that powers not specifically reserved to Westminster were devolved by default had “for the first time been broken in my view".

Cross-party amendments to the Bill were tabled yesterday in a bid to overhaul it to the devolved government’s satisfaction, to avoid a constitutional crisis in the spring.

Giving evidence to Holyrood’s European Committee, Lord Kerr said that if the Bill was not changed it could fail to pass in the Commons and House of Lords.

He said it was "almost 50/50" whether the UK would undergo a hard Brexit, leaving both the single market and the European customs union.

He said: "Next autumn's drama, autumn 2018, is the deal or no deal. And I cannot now see any negotiable deal for which there is a majority in the House of Commons.

"It seems to me there are sufficient hardline Brexiteers to make it very difficult for the Prime Minister to compromise sufficiently to get a deal in Brussels, and if she does these people might vote down her deal.

“I can see a situation in November/December when the outlines of the deal or no deal are becoming clear - November/December next year - and there will be a requirement for a parliamentary vote, even if it is no deal. At that stage we could be quite close to an election."

He criticised Brexit Secretary David Davis for "unrealistically" raising people's expectations about the UK's future outside the EU and said Foreign Secretary Boris Johnson was not delivering in Brussels despite "roaring like a lion".

Lord Kerr said: “At some stage the penny is going to drop between now and March 2019... the longer that moment of the penny dropping is deferred, the bigger the disappointment and the feeling of being let down in this country.

"Of course it will be blamed on the evil foreigners who haven't given us what we want."

Nicola Sturgeon last night told business leaders in Dublin that Ireland "has an ally in Scotland" in striving for a soft Brexit.