Jeremy Corbyn has told Theresa May that Labour MPs will vote against her Chequers plan unless she is willing to accept his proposal to keep Britain in a customs union and protect consumer standards and workers’ rights after Brexit.

Jeremy Corbyn’s conference speech – what’s the verdict? | Gaby Hinsliff and others Read more

The conditional offer came near the end of an hour-long speech at the Labour party conference in Liverpool, in which Corbyn tried to position himself as sitting in the mainstream of British politics, three years after he took control of the party.

The Labour leader told delegates: “As it stands, Labour will vote against the Chequers plan – or whatever is left of it – and oppose leaving the EU with no deal” in the meaningful final vote promised by May after the Brexit talks conclude in November.

But he held out the possibility of supporting May – who is struggling to contain a rebellion against her Chequers plan from the right wing of her party – on his terms.

“If you deliver a deal that includes a customs union and no hard border in Ireland, if you protect jobs, people’s rights at work and environmental and consumer standards, then we will support that sensible deal. A deal that would be backed by most of the business world and trade unions too,” he told delegates.

Corbyn concluded: “But if you can’t negotiate that deal then you need to make way for a party that can.” That prompted the loudest applause in his fourth keynote address as party leader, in which he argued that since the 2008 financial crash his brand of politics was what the country needed.

The leader highlighted policy ideas unveiled by party colleagues, such as worker representation on company boards, taxation of second homes and reversing cuts to council services and police numbers. He also made pledges on childcare and vowed to maintain the triple-lock on the state pension in a bid to appeal to older voters.

Facebook Twitter Pinterest The shadow Brexit secretary, Keir Starmer, listens to Corbyn’s speech. Photograph: Hannah Mckay/Reuters

“Conference, we are winning the public debate. We have defined the new common sense, and that’s where our party can stand united,” Corbyn said.

That, he said, explained the party’s relative success in the 2017 election, in which Labour gained dozens of seats and denied May control of the Commons. “That’s why Labour speaks for the new majority, why last year we won the biggest increase in the Labour vote since 1945, and why Labour’s ideas have caught the mood of our time.”

Corbyn’s carefully crafted statements on Brexit came at the end of a party conference that has been largely dominated by the European question, and in particular whether to support the idea of a second referendum following intense pressure from the party’s membership.

Delegates had supported a motion to keep open the option of campaigning for a second referendum if it cannot force a general election over the issue, but the compromise appeared to come unstuck when the shadow Brexit secretary, Keir Starmer, and the shadow chancellor, John McDonnell, seemed to contradict one another over whether remain should be an option on the ballot paper.

Play Video 1:57 'Nobody is ruling out remain as an option': Keir Starmer at Labour's Brexit debate – video

The Labour leader, however, stepped back from that debate as he focused his attack on May’s tortuous negotiations with Brussels. He said leaving the EU without a deal would be “a national disaster”, adding: “If parliament votes down a Tory deal or the government fails to reach any deal at all we would press for a general election.”

Referring obliquely to a second referendum, Corbyn added: “Failing that, all options are on the table.”

Corbyn’s declaration increases the chance of May not being able to get a final Brexit deal through parliament, given that the European Research Group faction in the Conservative party has repeatedly said it would also vote against Chequers.

The party leader accused May of being increasingly in hock to the her party’s right, saying that the main negotiations had been between “different factions of the Tory party”. He said that May and other cabinet ministers “see Brexit as their opportunity to impose a free market shock-doctrine in Britain” and cited the prime minister’s pledge made on Tuesday in a speech in the US to cut corporation tax to the lowest level in the G20.

On Thursday, Corbyn will meet the EU’s chief negotiator, Michel Barnier, to explain his party’s opposition at a time when European commission officials are increasingly concerned that the UK will be unable to agree a final deal, making them fear a no-deal Brexit is more likely.

May’s Chequers proposals would keep the UK signed to a common rulebook of standards for food and goods after the country leaves the EU. May has repeatedly defended the scheme, although the European commission has said it will come back with its own counter-proposals next month as Brexit talks reach their final phase.

No-deal Brexit would be 'national disaster', Corbyn tells Labour party conference – Politics live Read more

The speech contained few new policy pledges, instead citing announcements made by frontbench colleagues throughout conference; although Corbyn did, as had been trailed, promise a green energy policy he said would create 400,000 new jobs by 2030 and pledge that Labour would make 30 hours a week of free childcare available all two-, three- and four-year-olds.

Corbyn also referred to antisemitism, conceding the row over the issue had “caused immense hurt and anxiety in the Jewish community and great dismay in the Labour party”. He said he hoped it would be possible for the party “to draw a line” under the issue a month after the party adopted the full definition of antisemitism for its internal code of conduct as drawn up by the International Holocaust Remembrance Alliance.

He declared: “We will work with Jewish communities to eradicate antisemitism, both from our party and wider society. And with your help I will fight for that with every breath I possess,” and, reverting to first principles, added: “Anti-racism is integral to our very being. It’s part of who you all are, and it’s part of who I am”.

The leader did not reference any of the controversies about his own conduct; and he did not make the unconditional apology the former chief rabbi Jonathan Sacks had called for after audio emerged of Corbyn accusing a group of British Zionists of being unable to understand English irony.

But Corbyn did attack the Conservatives, and accused the governing party of double standards. “We won’t accept it when we’re attacked by Tory hypocrites who accuse us of antisemitism one day, then endorse Viktor Orbán’s hard-right government the next. Or when they say we are racist, while they work to create a hostile environment for all migrant communities.”

He said race hate was a growing threat in Britain, Europe and the US that had to be confronted and said a rising far right was on the rise “on the rise, blaming minorities, Jews, Muslims and migrants, for the failures of a broken economic system”.

Corbyn also appeared to accuse Theresa May of pursuing a similar approach. “Its victims include the Windrush generation who helped rebuild Britain after the war and were thrown under the bus by a government that reckoned there were votes to be had by pandering to prejudice.”