HSBC is taking on mortgage brokers with the trialling of a new "whole of market" advice service available to customers in its branches.

The lender will charge customers £150 to speak to a Mortgage Matcher consultant, who will offer impartial advice on the best mortgage deals available, including those from rival lenders. Customers who go on to take out a home loan from HSBC or First Direct, its online-only banking brand, will still be charged the fee.

The bank launched a seven-month trial in its Market Hill branch of Cambridge today. It plans to roll out the initiative to 19 other branches across London, the south east of England and Wales over the next three months. If proved successful, it will be available nationwide.

HSBC, which is the sixth biggest lender in the UK, has teamed up with John Charcol, a broker, to develop the scheme. John Charcol is providing trained consultants who will use Moneyfacts.co.uk, the free financial information website, along with "John Charcol best buy tables", to advise customers on the best deals.

The consultants will provide advice on the whole of the mortgage market, including direct-only deals not traditionally recommended by brokers, including John Charcol, such as those from HSBC or First Direct.

Direct-only deals have grown to dominate the mortgage market in recent months. More than two thirds of the mortgage deals available in the UK are direct-only, according to Moneyfacts.co.uk. It says 15 out of 20 of the recent best buys have been only available direct from lenders, over the phone, in branch or online.

HSBC and its online-only banking brand First Direct are currently top of a number of Moneyfacts best-buy tables and the lender admits that Mortgage Matcher advisers will frequently recommend its own deals.

Peter O'Donovan, head of mortgages at Bestinvest, a financial advisor, said: "This is a threat to brokers, who have already been hit by customers choosing to get mortgages straight from lenders."

Andy Mielczarek, head of retail products at HSBC, said: “We remain totally committed to funding our own mortgage business, with £15 billion available for 2009 – double what we lent in 2007. However this service offers our customers who are less confident in deciphering the right mortgage deal for themselves, another reason to talk to us and gives us more options to help them.

Melanie Bien, of Savills Private Finance, a broker, said: "This appears to be a natural step for HSBC, but other lenders, such as Bradford & Bingley, have tried, and failed, to offer whole of market advice in branch in the past."