looks suspiciously like Sycamore to me.

Oh no there are 4 of the buggers very close to each other. What a shame. Think they may need to go. That side of the garden is already lined with trees and we don't need anymore due to the lack of sunshine x

If you have a mature sycamore nearby you will get hundreds of seedlings, as many of us do. You will soon recognise the seed leaves as they re long and narrow. Very easily pulled at at this stage.
If you were asking abut the blossoming tree we need a closer picture.

Suggest you get rid of all four of the sycamores and consider whether you actually want the full grown tree in your garden and you'll have to deal with the seeds growing every year.

My first thought was "That's not a Sycamore! Not with buds and leaves in pairs!" Then my research showed that it was likely a Sycamore Maple (Acer pseudoplatanus)....Oh! ;)

If so they do get to be very large trees, 100 feet plus. Not sure I would want them in my garden even here where we have plenty of room for bigger trees.

We have several on our borders and some of them house part of a big rookery. So between the seedlings and the bird droppings we have lots of fun... I like them in winter with blue sky above as they are a lovely shape..
But yours in not in a good place and needs to come out.