Labour has urged the Tories to launch an investigation after a senior Conservative MP and a journalist accused Stanley Johnson, the Prime Minister’s father, of inappropriately touching them.

Former minister Caroline Nokes first accused the elder Mr Johnson of forcefully smacking her on the backside at the Conservative Party conference in 2003, ahead of him running to be a Tory MP.

Her allegation prompted political journalist Ailbhe Rea to say she was “groped” by the former member of the European Parliament at the party conference in 2019.

Mr Johnson has declined to comment other than to say he has “no recollection of Caroline Nokes at all”, while the Conservative Party is yet to say whether an investigation will be launched and Downing Street declined to comment on the allegations against the “private individual”.

Ms Nokes, chair of the Commons Women and Equalities Committee, suggested the Prime Minister’s father inappropriately touched her during the 2003 conference in Blackpool.

At the time, she was preparing for the campaign to represent the Hampshire constituency of Romsey during the 2005 election, during which Mr Johnson stood in Teignbridge, in Devon.

“I can remember a really prominent man smacking me on the backside about as hard as he could and going, ‘Oh, Romsey, you’ve got a lovely seat’,” Ms Nokes told Sky News.

“Stanley Johnson did that to me ahead of the ‘05 election, so it was Blackpool … 2003/4.

“I didn’t do anything and I feel ashamed by that … now I probably would.”

Shadow home secretary Nick Thomas-Symonds urged the Conservative Party to launch an investigation.

“The Conservative Party clearly needs to investigate a serious allegation like that, that happened at their party conference,” he told Times Radio.

“Caroline Nokes is a very senior member of parliament. She’s the chair of the Women and Equalities committee.

“But whether it is a very senior member of parliament, whether it is anybody who attended that party conference, whoever the victim is, it is for us to listen to the victim, to treat their allegation extremely seriously and sensitively.”

Home Office minister Damian Hinds did not commit to an investigation during an appearance on the same radio station.

“If there is an investigation to be had, if that is the appropriate course of action, then of course that will happen,” he said.

The comments from Ms Nokes, who has represented Romsey and Southampton North since 2010, prompted a separate allegation from Ms Rea, which the journalist for the New Statesman magazine said happened at the Manchester party conference in 2019, when Boris Johnson was Tory leader.

Ms Rea wrote on Twitter: “Stanley Johnson also groped me at a party at Conservative conference in 2019.

“I am grateful to Caroline Nokes for calling out something that none of us should have to put up with, not least from the Prime Minister’s father.”

Stanley Johnson lost the campaign to become an MP in 2005 but had served as a Conservative MEP between 1979 and 1984.

Mr Johnson, now 81, declined to comment to the PA news agency about both of the allegations.

But, regarding the initial accusation, he told Sky News: “I have no recollection of Caroline Nokes at all. But there you go … and no reply.”

On Tuesday morning, Ms Nokes tweeted: “Just wanted to thank the sisterhood for the solidarity and support today. You know who you are and you’re amazing.”

Downing Street declined to say whether an investigation would be carried out, with the Prime Minister’s official spokesman saying: “I haven’t spoken to the PM about this, it wouldn’t be one for me.

“I’m not going to be drawn into specific allegations against a private individual. Of course we would want anyone in any circumstance who feels they have been a victim of any kind of harassment to come forward and report them to the appropriate authorities.”