PLAID Cymru has joined with the SNP, the Green Party and the Liberal Democrats in calling for the UK to stay in the single market and the customs union after leaving the EU.

The party’s leader in Westminster, Liz Saville Roberts, MP for Dwyfor-Meirionnydd, met with the other opposition leaders at a cross-party summit in the UK’s Parliament, called to coordinate efforts to protect the UK’s place in the single market and the customs union after it leaves the EU.

Ms Saville Roberts released a joint statement with the leaders of the SNP, the Green Party and the Liberal Democrats, pledging to work together to prevent the unprecedented threat of leaving the single market, to safeguard jobs, incomes, and living standards from the devastation it would cause.

The Labour leader was left empty-chaired at the summit after refusing to engage in cross-party talks on the biggest issue facing the UK, despite 87 per cent of Labour members backing single market membership.

The statement signals an intention to call on the devolved Parliaments and Assemblies to work with the group, and Ms Saville Roberts has called on the Welsh First Minister – Labour’s Carwyn Jones, to work with the cross-party group in his leader’s absence.

The parties pledged to act as a united and effective opposition to a hard Brexit in the months ahead – with just 10 months to go before a deal is to be in place between the UK and EU.

With speculation over a devastating ‘no deal’ scenario the parties urged Theresa May to take the option “firmly off the table”.

The joint statement from Mrs Saville Roberts, Ian Blackford MP, Caroline Lucas MP and Vince Cable MP read: “Tory plans for an extreme Brexit represent an unprecedented threat to our economy that would destroy hundreds of thousands of jobs, and damage the incomes, livelihoods, and living standards of millions of people across the UK.

“Time is running out to avoid this economic catastrophe.

“There are now just 10 months before a deal is to be in place between the UK and EU.

“Ten months to put the brakes on plans to drag us out of the single market and customs union and to avoid the lasting harm this would cause.’

“Analysis from the Bank of England, Fraser of Allander Institute, the London School of Economics and many others, have revealed the devastating extent of a hard Brexit or ‘no deal’ scenario for Scotland, England, Wales, and Northern Ireland.

“Leaving the single market will cost jobs.

“Over 3,000,000 UK jobs are linked to trade with the EU – one in every 10 jobs.

“There is no such thing as a ‘jobs-first’ Brexit that includes terminating our single market membership – these outcomes are incompatible.

“Protecting jobs, incomes, workers’ rights and the environment is central to our efforts in keeping the UK in the single market.

“We warmly welcome the Trade Union Congress’ position which echoes these sentiments and hope to work with them in the months ahead.

“The UK government’s lack of preparation represents the chaos at the heart of the Brexit process. It is a disgrace more than 18 months after the UK voted to leave the EU, the government has not yet published an analysis of the economic impact.

“We are jointly committed to providing that opposition, and call on Labour to join with us – to fail to do so would be an abdication of responsibility, and would make Labour just as culpable for the lasting damage a hard Brexit would do to UK jobs and prosperity.”

A Labour Party spokesperson said in response: “This publicity-seeking meeting is little more than a political gimmick.”