Workers in the manufacturing heartland of the West Midlands faced the sharpest increase in unemployment during the recession, while London and the south-east were cushioned from the worst of the job cuts.

The unemployment rate in the West Midlands shot up from a pre-recession trough of 4.5%, to 10.6% by mid-2009, according to a new analysis by the Office for National Statistics – an increase of 6.1 percentage points, the sharpest in the country. Yorkshire and Humberside saw the next-largest increase, from 4.4% to 9.7%.

In the south-east, meanwhile, where the jobless rate was just 3.7% in mid-2005, unemployment rose much less sharply as the economy turned down, to hit 6.3% by the spring of last year.

According to the ONS data unemployment was rising in most regions before the economy officially plunged into recession in early 2008. But in London, with its booming financial services sector, unemployment continued to fall until mid-2007, when the first ripples of the credit crunch made themselves felt.

The findings published by the ONS, highlight the divergent fortunes of Britain's regions during the worst recession since the 1930s, and the tough task facing the government as it battles to rebuild the economy. The ONS will next week release its first estimate of GDP growth in the second quarter of 2011 – a key test of George Osborne's "plan for growth".

Brendan Barber, general secretary of the TUC, said: "Today's analysis confirms that regional labour markets went into decline well before the recession started, and that it will take time and sustained investment just to get areas of northern England back to their pre-recession position."

He warned that after dismantling the regional development agencies which had the job of spreading growth throughout the country, and replacing them with less well-funded local economic partnerships, the coalition had left itself with few tools to fix the widening disparities between different parts of the country.

The ONS has also looked below the regional level, to compare unemployment measured on the claimant count, which records the number of people receiving jobseeker's allowance in each local authority area.

Hull stands out as the city with the highest unemployment at any point during the downturn, with 8.4% of the workforce claiming unemployment benefit early last year. It remained the worst-hit place in Britain on the latest labour market data, with a claimant count rate of 8.1%.

Wolverhampton, in the West Midlands, suffered the second-highest claimant count rate, of 8%, and 7.7% of the workforce were still claiming JSA last month.

Low-skilled workers have fared worse than their better-qualified counterparts since the onset of the credit crunch, according to the ONS. Among the lowest skill category – cleaners and catering assistants – unemployment on the claimant count measure shot up by 5.3 percentage points, to 13.2%. Among the highest skilled workers, meanwhile – teachers and doctors, for example – it rose by just 1.1 percentage points, to 1.7%. Higher-skilled workers have also seen unemployment peak earlier, and fall faster.

Andrew Carter, director of policy at the Centre for Cities thinktank, said the differing fortunes of high and low-skilled workers could reflect underlying structural changes in the economy.

"There are just fewer low-skilled jobs now compared to the number of low-skilled workers," he said.

He added that these workers could come under more pressure, as the government's Work Programme, devised by Work and Pensions secretary Iain Duncan-Smith, shifts more people off sickness benefits or lone parents benefits such as income support, and into the workforce. They will receive tailored help to find them a job – but Carter said the risk is that firms are still not hiring. "The worry is really that given the conditions that we're in, the Work Programme is just about to massively increase the supply of labour, and if you increase labour at a time when there's stagnant demand, it makes you wonder what that will do for wages and terms and conditions."