Jo Brand has spoken of the need to maintain the momentum of the #MeToo movement despite the fact that some people are “fed up with it already”, recalling a charity event where a man forced his tongue into her mouth.

The comedian told an audience at the Hay festival she was at a corporate charity day at Canary Wharf where “they were all pissed, it was about nine o’clock in the morning”.

A man asked for a kiss in exchange for him giving £200 to charity.

Brand recalled: “I went ‘god all right then.’” She offered her cheek. “He stuck his tongue in my mouth … oh my God, it was disgusting.

“The thing was, I thought to myself: ‘This is a charity day, jolly, we’re raising loads of money … can I make a really massive fuss?’ To my shame, I didn’t. I just pretended it hadn’t happened and moved on.”

She said everyone at the event was having fun “and he just exploited that. It did really piss me off but I have had numerous attempts to put me down, to put me back in my box. It never stops.”

Brand was at the literary festival in Wales to talk about her book, Born Lippy: How to Do Female, which offers advice, both funny and serious, on how to navigate life as a woman.

She said it was good that women felt more permission to be angry but it still felt “not very angry and not for very long”.

“It seems what is happening with the #MeToo movement is that people are fed up with it already. It’s: ‘Oh I’ve listened to that for months, will you shut up now.’

“I feel it is something we need to keep pushing at. It was going in the right direction until certain people said, ‘Oh they’ve had their say, can they not be quiet now?’”

Some of that backlash has come from women, Brand said, adding “most of them work for the Daily Mail”.

Brand is a former mental health nurse whose career has gone from the 1980s alternative comedy circuit – as “the Sea Monster” – to something approaching national treasure status presenting shows such as The Great British Bake Off: An Extra Slice.

She was applauded by the audience of the BBC satirical show Have I Got News for You in 2017 after rebuking the all-male panel for not taking sexual harassment seriously.

Play Video 0:42 Jo Brand silences all-male panel on Have I Got News for You – video

After show regular Ian Hislop commented that some of the allegations emerging from Westminster were not “high-level crime”, Brand intervened by saying: “If I can just say, as the only representative of the female gender here today – I know it’s not high-level, but it doesn’t have to be high-level for women to feel under siege in somewhere like the House of Commons. Actually, for women if you’re constantly being harassed, even in a small way, that builds up and that wears you down.”

Her book contains advice for young people and parents, including people who are worried about their children watching online porn.

She told her Hay audience: “Just say to them: we’re all going to sit down and watch it as a family. Then you can say things like ‘Ooh, that plumber is very attractive … I must say those curtains are lovely.”