Greens, Scottish and Welsh nationalists to set out 'progressive' case to stay in Europe

With so much attention given to 'Project Fear', the campaign will aim to highlight the positive aspects of EU membership

Nicola Sturgeon speaking in Brussels for the first time as First Minister of Scotland (AP)

Scotland’s First Minister Nicola Sturgeon will join the EU referendum campaign fray on Monday, appearing alongside Plaid Cymru’s leader Leanne Wood, and the Green Party MP Caroline Lucas to set out “the progressive case” for voting to Remain.

With the Labour In For Britain campaign so far eclipsed by the clash between the Government and the Conservative-led Vote Leave group, Ms Sturgeon will seek to shift attention onto the social benefits of EU membership, including maternity rights.

The campaign event in London will see Ms Sturgeon reunited with fellow nationalist party leader Ms Wood, with whom she has enjoyed positive relations in the past.

Alongside, Ms Lucas, the leaders are expected to make a bid to change the debate on EU migration, hailing the benefits of freedom of movement.

Speaking at the SNP’s National Council meeting in Perth on Saturday, Ms Sturgeon said she was a “passionate” believer in the “positive, progressive case for EU membership”.

“The social protections and benefits that membership has given us – from maternity rights, to workers’ rights to freedom of movement - are almost so ingrained in our daily lives that it is easy to take them for granted,” she said.

“With the Tories itching to scrap the Human Rights Act and their attempts to curb Trade Union rights, it is clear that these social protections would not be safe in the hands of a Westminster government.”

The SNP leader will also meet with the new Labour mayor of London Sadiq Khan on Monday, in a head-to-head where the two leaders will discuss economic links between London and Scotland, and their shared opposition to a range of Tory policies, SNP sources said.

Senior Labour figures have in recent days raised the prospects that any future Labour government may have to work with the SNP. With recent Scottish election results seeing the party slip into third place, seemingly eradicating any hopes of a Labour resurgence in Scotland in the 2020 General Election, hopes of a Labour majority at Westminster are thin, and a number of Labour figures see some accommodation with the Scottish Nationalists as the only likely route to power.

Yesterday former Prime Minister Gordon Brown returned to the EU campaign trail, issuing a plea Britain’s nine million Labour voters and young people to turn out and vote on June 23. Polls have shown that Leave supporters are more likely to be older, and more likely to turnout to vote – a factor that gives the Leave campaign the edge in some polls.

Speaking at the Fabian Society, Mr Brown also urged mothers to vote to stay in the EU for the sake of their children.

“If we the British then decided we were going to walk away from our nearest neighbours, refuse to cooperate on economic and other matters that are vital to our future, deny young people in our country the chance to plan for the future because we are breaking off links to countries that are nearest to us, what sort of message would we send to the world about what kind of world we are going to build for the future if we could not engage in cooperation with our nearest neighbours?” he said.

"By the strength of our common endeavours we can achieve more together than ever we could achieve on our own," he added.