Gordon Brown’s hopes for a pre-election fightback founded on an emerging economic recovery suffered a severe blow as official figures showed the recession will be even deeper and longer than already feared.

Overhauled figures revealed that the economy slumped at its fastest pace for 50 years in the first quarter, plummeting by 2.4 per cent, far worse than previous estimates showing an already savage 1.9 per cent decline.

In a double blow, the rejigged numbers also indicated that the recession began a quarter earlier than has been thought.

The economy began to slide between April and June last year, and shrank by 0.1 per cent, instead of only slowing to the standstill previously reported.

City experts said the bleak figures would leave Alistair Darling struggling to achieve his worst-case prediction that the economy will shrink by no more than 3.75 per cent this year.

It is now more likely that the slump will spell a decline of more than 4 per cent, economists said.

To avoid that outcome, the Chancellor will need the economy to surge ahead in the second half of the year, they added. “He’ll be lucky to achieve it,” Jonathan Loynes, of Capital Economics, said. “This clearly leaves an extremely weak platform for growth this year.”

The scale of Britain’s economic plight at the start of the year was emphasised as the revised data also downgraded the year-on-year slump in GDP during the first quarter to a record 4.9 per cent, compared with the previous 4.1 per cent estimate.

“You’ve never had it so bad seems the most apt summary of the state of the economy in the first quarter,” Ross Walker, UK economist at Royal Bank of Scotland, said.

“It does serve to emphasise the hole out of which the UK must climb.”

Despite the grim news, the City still expects that the worst phase of the recession has passed, and that the quarter just ended will have seen a much more modest fall in GDP.

Some leading economists even believe that anaemic growth may have already resumed in the past few months.

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