Hardline Brexiteers “had their chance and failed”, Nicola Sturgeon has said, as the SNP’s Westminster leader pledges to push for a Commons vote on the single market.
Scotland’s First Minister said there was a “golden opportunity” for moderates to press for continued single market and customs union membership.
It came as Ian Blackford, her party’s Westminster leader, revealed he was working with the Liberal Democrats, Plaid Cymru, and Green Party to amend the EU Withdrawal Bill at report stage.
If their bid is successful, ministers would be blocked from using so-called Henry powers to amend primary legislation and drag the UK out of the single market and customs union.
Sturgeon said: “More than 18 months on from the Brexit vote, it beggars belief that the UK Government is not only still unable to say what kind of relationship it wants with the EU, but has also failed to produce any meaningful economic assessment of the different possibilities.
“Bluntly, the hard Brexiteers have had their chance and failed.”
Theresa May has vowed that Brexit will include taking the UK out of the single market, though the Prime Minister has left herself with maximum room for manoeuvre on regulation surrounding the customs union.
Sturgeon added: “[Hard Brexiteers] have completely failed to explain how their approach could even remotely come close to replacing the enormous lost trade and investment of leaving the single market.
“That means there is now a golden opportunity for those moderate voices who are making the case for Scotland and the UK to remain in the single market.
“It will be a fundamental dereliction of duty as Prime Minister if Theresa May continues to pursue her red lines without providing information on their impact and publicly discussing the options available.”
Labour leader Jeremy Corbyn was empty-chaired after declining an invitation from Blackford to attend cross-party talks on blocking hard Brexit in Parliament last week.
Shadow Brexit Secretary Keir Starmer has said the party wants to remain “in a single market and a customs union” but does not support full membership beyond a transition period. Around 87% of Labour’s rank and file back single market membership, however, a recent Mile End Institute survey found.
Some pro-EU Labour MPs, such as Chuka Umunna and Chris Leslie, could choose to back the cross-party amendment. However, the Parliamentary arithmetic would require all Labour MPs and Remainer Tories to rebel against their leaders.
A Labour Party spokeswoman said: “This amendment would not keep the UK in the single market and customs union, nor does it intend to deal with the serious flaws in this Bill.
“Labour has been clear that we want a…