Some estate agents will pressure you into using their mortgage brokers and solicitors that are in house.
Some Estate agents may do this to hit their referral targets or to earn further commission or just for ease of communication however you need a solicitor and broker who will work solely for you to ensure you get the best service at a suitable price whilst offering impartial advice.
We would always advise to shop around for quotes of multiple solicitors and reading through all the documents provided to ensure there are no hidden fees involved. Some mortgage brokers are also not whole of market/Independent so sadly they do not have access to all the lenders who could offer you a lower rate or who could accept your circumstances.