Small building firms face going to the wall after being told by Birmingham City Council they could be squeezed out of local authority contracts in favour of larger national firms.

A total of more than 50 building, plumbing and electrical firms which regularly carry out adaptations to properties to enable disabled or vulnerable elderly people to live independently at home have been told that their contracts are under review.

Adaptations, which include walk-in showers, moving sockets and switches, widening doors and installing wheelchair ramps, have until now been carried out by small traders.

The builders fear that the council’s housing and neighbourhoods department wants to appoint three or four contractors, one for each quarter of the city, to make all the alterations.

A similar set-up is used for council house repairs and maintenance which is carried out by two firms, Willmott Dixon and Mears Group Plc.

The council has confirmed it is carrying out a review of its contracts and that current providers will have an opportunity to bid.

Opponents believe it will not only drive down the quality of the work, but cost local jobs and lead to the closure of small businesses and suppliers.

They also fear that a new corporate contractor will simply take on the same staff or sub-contractors at lower rates of pay, while the difference is taken away from the city in profit.

One of the firms, Goodwells Ltd, based in Birchfield Road, Perry Barr, has been installing showers, ramps and converting houses for disabled and elderly residents for 22 years, and before that owner Andrew Redmond worked for the council for four or five years as a sole trader.

The firm provides work for more than 20 people.

He said: “Our whole business is under threat. We do some work for Sandwell Council and some private work but we could not sustain our business on that. We need the Birmingham City Council contracts.

“We provide a service, we do it better than the big companies, we get better customer satisfaction and we do it cheaper.

“The new firms may well charge the council more, employ us as sub-contractors for less and cream off the difference. That’s what happened with the housing repairs. The large firms get bigger and the little ones get wound up.”

He pointed out that the money the council spends on his firm stays in the local economy and provides work for people in Birmingham.

A knock-on effect will also be felt by suppliers such as Handsworth-based Atlantic Joinery. Owner Balwant Bhogal said: “As a supplier we will be affected.

"These larger companies will have their own suppliers and their own workshops, probably elsewhere in the country, and will use them.”

A group of firms in Perry Barr, Handsworth and Ladywood have set up a co-operative to campaign to keep their contracts and are supported by local Labour MP Khalid Mahmood.

Mr Mahmood said: “It is extremely disappointing that local business people are being pushed aside for larger contractors. These large companies are not based in Birmingham, many of the people they employ are not from Birmingham.

“The smaller firms are based here, live here, work here and spend their money here. Our Labour council has made local employment a priority so I call on them to support these businesses.”

Mr Mahmood has written to council leader Sir Albert Bore asking him to drop the plans and believes his political colleagues will ‘‘see sense’’ and protect local jobs and businesses.

A Birmingham City Council spokesman said: “It is business as usual for contractors working on Disabled Facilities Grant work. However, we have a duty to review contracts to ensure best value is achieved, and now is the time to start that review.

"We are exploring all options, and we will look to ensure all current contractors have an opportunity in the procurement process.’’