It looks like a mint that is flowering. Most gardeners do not let the mints bloom as they lose flavor and the flowering takes away from the plant producing flavorful leaves. Cut the flowers off and force growth back out of the base of the plant.

thanks for the comments! The leves are quite long and narrow. But have a rectangular shape. They are attached to a stiff upright stem and grow in clusters from the base of a wall. I am amazed at the various bees here in north Wales, they all love it.!

The stems in the mint family are typically ‘square’, with four flat vertical sides. The flowers look to be mint-like, as do the flowers. If the stems are square and it smells like mint…it’s probably a mint.

Looks like mint to me.