What has overtaken my wildflowers patch?

[Rattysparklebum]

I have a small corner of my garden that has been a wildflower patch for about 3 years and usually has a good mixture of different flowers that have self seeded until this year when it has been overtaken by this pink thug, what is it?

Rosebay willowherb?

ladyface69 thanks, I just googled rosebay willow herb but it’s not that, I think my photo is not very clear though which doesn’t help!

Red Campion.

I’ve been googling and it looks most like a type of mallow, thanks for the suggestions though

Pink campions!