Pressure is mounting on Jeremy Corbyn to back a second Brexit referendum after 10,000 Labour members and supporters demanded his party switch position.

The appeals to the Labour leader were made via a survey carried out by the People’s Vote campaign and underline a groundswell of pro-second vote support among the party’s grassroots. 

It comes as Corbyn prepares to make a high-profile speech in Yorkshire and ahead of MPs voting on Theresa May’s Brexit deal next week. 

Labour Party policy is for MPs to vote down the prime minister’s deal and attempt to force a general election. After that “all options”, including campaigning for a re-run of the referendum, will be considered by Corbyn’s frontbench. 

But the research – which saw 5,521 party members, 2,373 Labour supporters and more than 2,000 submissions from Labour for a People’s Vote supporters get in touch – shows Labour backers want Corbyn to take an immediate pro-second referendum stance. 

One member, called Anne Hignett, had particularly strong words for Corbyn, accusing him of deciding policy behind-closed-doors rather than with members. 

She said: “I despair of the Labour leadership’s stance re Brexit: purporting to support the unemployed and low paid yet supporting Brexit, which will further devastate their lives; purporting to value democracy yet utterly ignoring the views of most party members and Labour voters, specifically by not supporting a people’s vote and remaining in the EU. 

“The leader’s behaviour often seems surreptitious rather than promoting open debate.” 

Hignett went on to say she was “distressed that the leadership also seems unwilling or unable to work across the spectrum of opinion”, adding: “The leadership has entirely failed to provide positive, constructive, restorative leadership at a time when society is so bitterly divided.” 

Another member, Bill McCarthy, responded after standing down as a Constituency Labour Party (CLP) chair after six years. 

He said he believed members were 9:1 in favour of remaining in the EU and Corbyn risked damaging the morale of activists if he ignored members’ strength of feeling. 

“If we do not see a change to the policy on Brexit, the lack of enthusiastic members will be reflected in our performance in the local elections in May and in any general election,” he said. 

Another member, David Cox, told the survey: “The leadership needs to have the courage to start leading over the critical few days left to us to stop this unfolding disaster.” 

He added: “To be allied with UKIP is a travesty of everything Labour stands for.” 

Another member, Jason Kelly, said Labour would struggle to get members to go door-knocking if they felt ignored on Brexit.

He said: “The conference motion specifically names ‘campaigning for a public vote’ as an option. Indeed, it is the only option mentioned. Therefore, it is crystal clear which option party members currently favour.”

The party’s International Policy Commission, which will consider Brexit, gathers for a meeting on Wednesday. 

It brings together members of the party’s ruling National Executive Committee, trade union bosses, shadow cabinet members including Sir Keir Starmer and Emily Thornberry and elected National Policy Forum members. 

Thornberry appeared prepared to push back against calls for a policy change on Sunday, however, when she told the BBC the People’s Vote campaign thought its job was to “slap the Labour Party around”. 

She added some saw the campaign as “an opportunity to attack the Labour Party and the leadership of the Labour Party”. 

While a recent YouGov poll found support for a second referendum as high as 75% among Labour voters, there has been little evidence of a shift toward remain overall. 

It comes as left-wing figures including the economist Ann Pettifor and TSSA union general secretary Manuel Cortes set up the Left EU Strategy and Policy Commission, a new group which will set out an alternative ‘remain and reform’ agenda it hopes Labour will adopt. 

Mike Buckley, director of Labour for a People’s Vote, who is among those on the new body, said: the “only democratic way ahead is a public vote”. 

He added: “A return to 2016, however, is not enough.

“Our country is in dire need of reform, all the more so after eight years of Tory austerity and failure. The Labour Party should use a people’s vote campaign to put forward a ‘remain and reform’ policy programme that, if enacted in government, would make both the UK and the EU fairer, more equal and more secure.

“We can only deal with the shared crises we face, including climate breakdown, global instability due to the increasing belligerence of Russia and the unpredictability of a US led by Donald Trump, and insecurity caused by an over-reliance on the market and a lack of public investment and control, by working together with our European partners.”