Regional development agency Yorkshire Forward said it was liaising closely with the stricken bank and was ready to mobilise its special taskforce, activated whenever a business lays off a number of people which will have a "significant" effect on the regional economy.

Calderdale councillor Paul Rogan said it would be devastating for the town if there were job losses on the scale being reported. "There would be a deafening crash across Calderdale and beyond if that happened," he said.

"We all know what happens in these situations – it is the company that is doing the taking over that keeps its staff, that is Lloyds, and the company that is being taken over, that is HBOS, that sheds staff. It's not rocket science.''

The acting leader of Calderdale Council, Stephen Baines, said he was very concerned.

He said: "I am concerned if one job is lost and if it does go ahead there are likely to be job losses.

"We have always tried to work to preserve as many jobs in Calderdale – after all, HBOS and the council are the two biggest employers in the area.

"People who work for HBOS tend to live in the area so it will have an effect on the local economy."

But staff in the Halifax head office were working normally.

Deborah Durkin, 39, from Bradford who works in the fraud department, said: "It's just business as usual to be honest, we have not been told anything and people are just getting on with their jobs.''

Latest figures show that unemployment in Yorkshire has soared over the summer with a further 24,000 jobs lost in three months.

The total number unemployed in the region now stands at 163,000, or 6.2 per cent of its population, in the measurements from May to July this year released by the Office for National Statistics.

It is the second highest rise of any region with only the South East registering a greater number in the quarter – 28,000. Third-placed region is the East Midlands with 13,000. Four regions saw employment rise.

Tony Cherry, regional chairman of the Federation of Small Businesses, said it was mostly companies employing less than 50 people which were shedding jobs in a desperate attempt to stay afloat in worsening economic conditions.

He said: "We're not seeing the announcements of large-scale redundancies in Yorkshire so these numbers seem to be coming from small and medium sized businesses, which is very concerning for us.

"What is certain at the moment is that small businesses are finding it hard to pass on the increasing cost of materials, gas and fuel and are often carrying out contracts at a loss, which is not sustainable."

Sectors in the region doing particularly badly include haulage, legal and financial services, building and property sales.

Nick Pontone, director of policy at the Yorkshire and Humber Chambers of Commerce, said: "It's not surprising that job losses are jumping up but it does surprise me that Yorkshire is losing jobs quicker than other regions.

"There's a feeling now that the last domino is toppling – first it was business confidence then order books then sales, and now jobs is the last domino to go. We will not see any shafts of light until business confidence picks up."

Thea Stein, director of economic inclusion at Yorkshire Forward said it was working closely with Job Centre Plus, local authorities and employers to ensure people who lost their jobs had access to the vacancies being created in the region.