JEREMY Corbyn has been told by Ian Blackford not to trust the Tories to stick to their side of any Brexit compromise deal. The warning from the SNP’s Westminster leader came amid claims that Downing Street is prepared to offer the opposition a so-called “Boris lock”, guaranteeing that any agreement reached between the Tories and Labour can’t be torn up by the Brexiteer toff who is likely to become the next Prime Minister.

Blackford also warned that Labour will “pay the price at the ballot box” in Scotland if a deal with the Tories increases the risk of a hard Brexit.

Theresa May infuriated her party last Tuesday when she initiated talks with the Labour leader in an attempt to find a way to get her defeated Brexit deal through the Commons. She hopes to secure some form of consensus before a European Council meeting on Wednesday, when she will ask for the Brexit deadline to be pushed back until June 30.

The talks with Labour broke down on Friday night with accusations that the Tory leader had been unwilling to shift on her red lines. However, teams from both parties are due to meet again today to try to find a way forward before May heads back to Brussels.

One proposal being put forward by the team at Number 10, according to The Sunday Times, is change to the government’s Withdrawal Bill so that Labour’s demand for a customs arrangement is enshrined in law. That would mean any future Prime Minister would have to overturn primary legislation to get a hard Brexit. However, speaking on the BBC’s Andrew Marr Show, Brexiteer Cabinet minister Andrea Leadsom warned that “no government binds the hands of a future government.”

Blackford was also sceptical of the “lock”, warning that if someone such as Johnson were to become Prime Minister, the risk of a hard Brexit would be “very real”. He told the BBC’s Sunday Politics Scotland: “I would say to colleagues in the Labour Party: be very careful because if you do allow this deal to get through ... we know Theresa May is going to go. You could end up with someone like Boris Johnson as Prime Minister and quite frankly he can come along with any legislation he chooses.

“There are no guarantees through this process, and the risk of having a hard Brexit, having Scotland being outwith not just the single market and the customs union, would be very real. I would say to Labour: don’t do this, be very careful with what you are doing or quite simply you will pay a price at the ballot box in Scotland.”

Blackford said the Prime Minister was asking Corbyn to effectively be the “midwife of Brexit”.

May’s decision to reach out to Corbyn for help getting deal through has led to criticism from many in her own party. Leadsom said the Tories were working with Labour “through gritted teeth”, although Labour front-bencher Rebecca Long-Bailey, who was involved in the meetings with the government, told Marr they had been “very good-natured”.

She said Labour was “hopeful”, adding: “The sad thing is at the moment we haven’t seen, overall, any real changes to the deal, but we’re hopeful that will change in coming days and we are willing to continue the talks, as we know the government are. But we are currently waiting for the government to come back to us now to state whether they are prepared to move on any of their red lines.”

The Labour MP also said the party would support a vote to revoke Article 50, the legal mechanism through which Brexit is taking place, if it looked as if the UK was heading for no-deal. Corbyn is under increasing pressure from many of his own MPs to make a second referendum the bottom line of any agreement he achieves with the government.

Over the weekend, a new poll revealed that two-thirds of Scottish voters now want to have their say on the Brexit deal. A survey of 9500 adults around the UK – commissioned by campaign group Right to Vote – found high levels of support for a new referendum north of the Border. The poll asked whether, if Parliament cannot decide on the best way forward for Brexit, voters would support or oppose a public vote on whether Britain stays in the EU, leaves the EU on the terms set out in the government’s deal or leaves the EU with no deal.

Some 68% of voters in Scotland who expressed a view want a final say on Brexit, with 32% against that idea.

Overall, nearly three out of five (58.1%) voters who gave a view now want a final say. Right to Vote said this is a majority view in nine out of 10 constituencies across Britain.

The UK is due to leave the EU on Friday and, as yet, no withdrawal deal has been approved by the House of Commons. It is possible, though unlikely, that it could crash out with no deal.

Leadsom claimed that scenario would be “not nearly as grim” as many believe. She said: “The civil service has done an amazing job of ensuring we minimise the problems. I’m not an advocate for no deal, but it would not be nearly as bad as many like to think.”