Small White Flower On Rose

[LittleMissSleepyUK]

Does anyone know what this is? They’ve never appeared on the rose bush before but I am very new to roses so for all I know it might be normal

It looks like a wild rose - most roses are grafted onto wild rose rootstock and sometimes the rootstock will produce growth.

Shall I just chop that section off?

This happened to my expensive David Austin rose. When I looked more closely I could tell by the slightly different leaves which branches to chop off.

If you leave it, the white rose will eventually take over and the grafted rose would die off. If you were my DH (who hates multi-petalled roses) this would be a Good Thing. But if you want to keep your rose, then follow the stem of the white rose back to the base, and cut it off, along with any other stems that you can recognise as suckers. You’ll see (it’s quite clear in the photo) that the leaves of the suckers have three pairs of leaflets and a terminal leaflet, whereas the leaves of the grafted rose that you want to keep have only two pairs of leaflets and the terminal leaflet.