Agree with
stone on first one: that's a Maple species (
Acer sp.) of some sort, perhaps
Acer pseudoplatanus. Note opposite arrangement of simple leaves. There are more than a few Maples that can grow in Northumberland. Check for parent trees nearby.
I disagree with
stone on the second one, since it also has opposite arrangement - but this time pinnate compound leaves. It cannot be a Walnut or
Ailanthus altissima, because those both have alternate arrangement of pinnate compound leaves.
Your second plant is an Ash (
Fraxinus sp.), maybe
Fraxinus excelsior. Once again, Northumberland is probably home to more than a few European species of Ash. Those prominent and black terminal buds should be a clue to a final ID.
@Silversurfer likely knows these trees intimately...
