England UK

hi,
We have just signed up for a new mortgage and our mortgage lender
offered to arrange our B+C insurance at a 'competitive' rate......when
we saw their 'competitive' rate we informed them that we would sort out
our own insurance. they have now informed us in writing that if we do
not take out their insurance they will charge us an initial fee of
£50.00 and a charge of £25.00 annually for the duration of our
mortgage to cover their costs for 'checking' whether we have adequate
cover.
is this legal ??

thanks
alan