Glebionis segetum - Corn Marigold
This is an arable weed which is decreasing in it’s native area - the south of England. However, it is often included in “wild-flower” mixes and may persist or even spread for a year or two.
It has daisy-like flowers 3 - 7cm across with orange-yellow centres and golden-yellow rays. The leaves are lobed, grey-green and sometimes fleshy.