Mr Corbyn accused Theresa May of fomenting a "war between the generations" by playing off old against young in her election manifesto.
Mr Corbyn also reiterated his party's commitment to ensuring the pension triple lock, ending the freeze on working age benefits, free school meals, improving public housing and ending tuition fees.
At the time, a spokesperson for Mr Corbyn dismissed the news as "another silly story from a Tory paper".
The Liberal Democrats fell 1 point to 7 percent while the UK Independence Party gained 1 point to 7 percent.
Crucially, it puts Labour comfortably above the 30.4% share of the vote achieved by Ed Miliband in 2015, a benchmark which some supporters argue should remove pressure on Mr Corbyn to quit if he fails to win power.More news: Video Shows Turkish President Recep Tayyip Erdogan Watching Attack on Washington Protesters
Jeremy Corbyn has insisted the political tide is turning Labour's way as he spoke to hundreds of supporters in Birmingham.
It all comes as opinion polls in both the Mail on Sunday and The Sunday Times, the first to be published since the manifesto launch, suggest Labour is chipping away at the Conservative lead.
That was down from a Conservative lead of 18 points one week ago, the newspaper said.
The 35 per cent support for Labour recorded by YouGov is the best rating for the party since March previous year before the European Union referendum and challenge to Mr Corbyn's leadership. "Get on any bus, get on any train, go in any café and talk to people - the whole discussion and the whole debate is unravelling from the Tory point of view".
"They can get better again if we make June the end of May".More news: Melania, Ivanka Skip Headscarves in Saudi Arabia-Despite Trump Criticism in 2015
"That's why we are calling on the Tories to drop their anti-pensioner package immediately - older people should not be used as a political football".
The Labour leader was probed over fears that he could have been a threat to national security at a time when he was supporting convicted terrorists and campaigning for a unified Ireland, The Telegraph reported late Friday.
But the Prime Minister fought back by saying that a shadow cabinet row over the renewal of Britain's Trident nuclear deterrent showed that Mr Corbyn could not be trusted to defend the country.
"Things did get better under Labour". "The cold hard fact is that if I lose just six seats I will lose this election, and Jeremy Corbyn will be sitting down to negotiate with the presidents, prime ministers and chancellors of Europe", she said in a Facebook post.
A source said Trident would be included in a Labour government's strategic defence review but it would be look at issues like "costings", and how to protect the deterrent from cyber attacks.More news: Trexit? Online bettors play early end to Trump presidency
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