Gordon Brown in drive to rally Labour voters behind Remain campaign
Labour supporters have "most to gain" from keeping Britain in the EU, Gordon Brown will say as he spearheads a referendum charm offensive.
With just nine days until the country decides whether to terminate its 43-year stay in the bloc, Opposition figures are being thrust centre stage in a late bid to seize the initiative.
Pro-EU leaders are concerned that the potentially pivotal group of voters in a tight tussle are being pushed towards Brexit by the campaign's focus on Tory rivalries and immigration.
But Mr Brown will argue their interests are best served by keeping the UK at the table in Brussels to secure reforms to boost jobs, cut bills, enhance workers' rights and tackle tax havens.
Fears over the impact of foreign workers on local communities would be better addressed by insisting on more money to boost stretched public services than ending free movement rights, he will argue.
Only a handful of Labour MPs have broken ranks to back the Leave camp - but leader Jeremy Corbyn has faced claims of giving only lukewarm support to the party's official position.
Backbencher Gisela Stuart - who chairs Vote Leave - said " no amount of hastily cobbled together relaunches" would win back Labour backers who have "seen through the spin of the Government".
Mr Brown - whose late intervention in the Scottish independence referendum was considered an influential factor by some observers - will set out his "positive" message in a speech.
The UK would be "in pole position" to champion change when it takes the rotating presidency of the EU in 2017, he will say.
"From now until 10pm on June 23 we will not rest and I will not stop explaining why nine million Labour voters have most to gain from remaining in the EU," he will say.
"Today I am setting out a positive agenda for Labour voters - reasons why Labour voters should vote Remain and the patriotic case for remaining in Europe.
"Voting to Remain is about a positive, stronger future and is the alternative to a Tory Brexit. It is stronger for jobs, for rights at work and maintaining a British voice on the world stage.
"But we shouldn't just be a member of the European Union. We must be the leader of the European Union."
Deputy leader Tom Watson said: "If the Leave campaign wins, it will be a Tory Brexit that we face with all the consequences for jobs, pay packets and public services in Labour's heartland areas.
"It won't be those who are best off who are hit most by a Tory Brexit, it will be the least secure and most vulnerable in society.
"Gordon's agenda shows that Labour people can vote with confidence for what a reformed EU can and will do for working people".
Mr Brown will argue that reforms to digital, energy and service sectors could create an estimated 500,000 new jobs in Britain over 10 years - and that a pooled energy strategy could cut domestic bills.
The EU's "collective clout" could force action against tax dodgers and secure better protections for workers on zero-hour contracts, he argues.
He is also proposing a European solidarity fund to help communities in which healthcare, schools and public services are under pressure because of sharp population changes.
And a fight by Britain for a large slice of up to 16% of a 315 billion euro (£242 billion) infrastructure initiative to help industries such as steel hit by closures and restructuring.
Ms Stuart said: " We had an opportunity to get positive changes out of the EU but David Cameron blew it with his failed renegotiation.
"Labour voters have seen through the spin of the Government which is why they are rejecting the In campaign and no amount of hastily cobbled together relaunches will change that."