Boris Johnson insisted that allegations around his personal life would not be allowed to overshadow the Conservative Party conference.
The prime minister was forced to deny claims that he squeezed the thigh of a female journalist under the table during a private lunch.
He has also faced allegations about his relationship with American entrepreneur Jennifer Arcuri and whether she enjoyed preferential treatment while he was mayor of London.
Questioned about journalist Charlotte Edwardes’ claim that Johnson squeezed her thigh at a private lunch at the Spectator magazine’s HQ shortly after be became editor in 1999, Johnson denied it.
Asked if he had done it, he told reporters during a visit to a business in Manchester: “No, and I think what the public want to hear is about what we are doing to level up and unite the country.”
Asked if she had made it up he said: “I’m just saying what I’ve said. What the public want to hear is what we are doing for them and for the country and the investment in ways of uniting the country.”
The prime minister, who was visiting a cash and carry business in Manchester, denied that the rows over his alleged conduct were overshadowing the conference – “not at all”, he said – and hinted that the storm could be linked to opponents of Brexit.
“I think what the public want to hear is what we are doing to bring the country together and get on with improving their lives,” he said.
“I think I would make one general comment. I think there is a lot of people who basically want to stop us delivering Brexit on October 31.
“But I have to tell you we are not going to be deterred from that ambition. We are going to get on and do it, we are going to get us over the line.
“I think that that is the best thing for the country because it’s been going on a long time now, this row over Brexit.”
Cabinet ministers rallied around the prime minister after health secretary Matt Hancock said on Sunday that he would “entirely trust” Edwardes.
The health secretary refused to comment further on Monday.
“I haven’t got anything more to say on this,” he told the PA news agency as he was ushered away from a conference fringe event by aides.
Conservative Party chair James Cleverly told BBC Radio 5 Live’s Emma Barnett: “I know Boris Johnson very well, and if Number 10 say it didn’t happen, I believe that.”
Chancellor Sajid Javid said he has “full faith” in the prime minister.
He tried to evade questions about the row in a series of broadcast interviews.
“I don’t think it’s a good idea to get drawn into personal allegations,” he told the BBC.
“For my part, I’m not going to get into that.
“The prime minister has said that this is completely untrue. I have full faith in the prime minister, I don’t doubt what he has said for a second but I’m not going to get drawn into these allegations.”
In a sign of Tory frustration that questions about Johnson’s behaviour are taking attention away from policy announcements at the Conservative Party conference, Javid acknowledged he would “rather be talking about the infrastructure revolution” he has promised.
Former Tory cabinet minister Justine Greening, who now sits as an independent, told BBC Radio 4’s Today programme: “I can’t comment on those accusations but they are deeply concerning and in a sense they go to the heart of this question about character and integrity of people in public life and what standards the electorate have a right to expect.”
Javid used the conference to set out plans for investments in roads, buses and broadband.
He is outlining the first projects that will be included in the promised road investment strategy, a £5 billion package to support the roll-out of broadband and a £220 million fund for buses.
The claims about Johnson’s behaviour were made by Edwardes in her first column for the Sunday Times.
She said: “I’m seated on Johnson’s right; on his left is a young woman I know.
“More wine is poured; more wine is drunk. Under the table I feel Johnson’s hand on my thigh. He gives it a squeeze.
“His hand is high up my leg and he has enough inner flesh beneath his fingers to make me sit suddenly upright.”
After the lunch, she said she had confided in the young woman who was sitting on the other side of Johnson, who told her: “Oh God, he did exactly the same to me.”
Shadow secretary for women and equalities Dawn Butler said it was a “shocking but sadly all too familiar story”.
“What is it about powerful men feeling entitled to harass women? Boris Johnson has serious questions to answer,” she tweeted.