The price of bread (like everything else) has shot through the roof recently. This doesn’t mean that there are not two small crumbs of comfort for Gordon Brown and the Labour Party in the Crewe & Nantwich by-election result, and one rather more tempting morsel for the Labour Party, but emphatically not for the Prime Minister.

Yet these are small crumbs indeed. The first is that the slump in the Labour Party vote at Crewe was not noticeably worse than in other by-elections in the past five years, indeed it was an improvement on some of them. Labour lost over a third of its 2005 vote on Thursday, which was a little worse than in the Hartlepool by-election of September 2004, but about the same as Dunfermline and West Fife in February 2006 and Brent East in September 2003. Labour actually lost more than 40 per cent of its previous total in Birmingham Hodge Hill in July 2004 and almost half at Leicester South on the same day. So by recent standards, the collapse in the Labour vote under Gordon Brown is not that spectacular.

The difference, of course, is that in all the other by-elections mentioned above it was the Liberal Democrats, not the Conservatives, who picked up the support that the Labour Party was haemorrhaging. That fact alone means that the impact and the pain of this defeat is the equivalent of all those other setbacks put together.

This leads to the second crumb of comfort, although you might need a microscope to see it. In a sense, this was a trouncing of Labour’s own quite conscious choosing. When Gwyneth Dunwoody died, Downing Street had two options in terms of by-election timing. The first was to take it on the chin as swiftly as possible with the risk that it would become a referendum on the Government and hence a heavy loss to the Tories (who were well positioned in second place). The second was to wait until July and allow the Liberal Democrats the time to build up their support so that they would have a realistic chance of victory.

A triumph for Nick Clegg would have been far less embarrassing (and less novel) than one for David Cameron. Labour toyed with playing it long but feared that the Tories might win in July regardless with the Lib Dems second and themselves third, and that would be a dire catastrophe.

The crumb that does not require 20/20 vision to locate comes from relatively recent political history and the amazing, spooky frankly, similarity between this by-election and one held at Mid-Staffordshire in 1990.

The Mid-Staffs contest occurred in the third year of the 1987-1992 Parliament. It happened at a moment when the popularity of the Conservatives had sharply and suddenly slumped because of a change in tax policy (the Community Charge then, the 10p band rate now) and because signs of a sharp economic downturn with rising prices had emerged (ditto, 2008). The campaign was considered an unusually significant test of whether the Leader of the Opposition could win seats outside of his own heartland (Neil Kinnock and Middle England before Mr Cameron and northern England).

The Conservatives then began with just over 50 per cent of the vote from the last general election (Labour had just under 50 per cent in Crewe). Their candidate suffered an 18.3 percentage point fall in their share of the vote (Ms Dunwoody II endured exactly the same fate, 18.3 percentage points down, in Crewe). The victorious Labour contender won just over 49 per cent (as did Edward Timpson also on Thursday) and the swing (21 per cent) was even more sensational than that of Crewe (17.6 per cent). The then Political Editor of The Times (Robin Oakley) duly reported the next day that if this switch in sentiment “were to be repeated nationally at the next election, every single member of Mrs Margaret Thatcher’s Cabinet save John Major, the Chancellor of the Exchequer, would lose his seat”.

This did not happen. Far from it. Despite a continuing economic malaise, ministers won a surprise fourth term in office (recapturing Mid-Staffordshire as they did) in part because voters remained to be fully convinced that the Opposition had changed sufficiently. The Tories did, however, have to dump their leader in order to find salvation. No crumb of comfort there for Mr Brown.

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