The effect of this, the reports agree, would be to raise the minimum hourly rate for workers in London from £5.35 to £6.90 while cutting that for workers in the North East (£4.78), Yorkshire (£4.95), Northern Ireland (£4.80) and Wales (£4.84).

All rather odd since the national minimum wage has been one of Labour's flagship achievements from ten years in government.

Even so, the Sunday Telegraph last weekend reported that the prime minister was "understood to have been persuaded by academic studies" that having a single national rate was "uneconomic". The story went on to a "senior Labour source" as saying that a regional minimum wage would be the "logical next step".

From there the story has spread to local papers in Northern Ireland, Wales and the West Country.

Not one paper has a named Labour Party or government source putting forward this rather peculiar proposal – though plenty of local politicians from other parties have lined up to condemn it.

So where does the story originate? Reading carefully through the vast number of column inches devoted to it, there is just one source – a paper produced for the Economic Research Council by a visiting professor at Derby University.

The ERC, it should be noted, is doubtless, a fine organisation but it is a charity with no official government standing.

David Smith, the author of the paper, likewise, no doubt knows what he is talking about. But he is basically a retired City economist who is acting chair of the "Shadow Monetary Policy Committee" run by the Institute for Economic Affairs – hardly an official government institution.

And the paper on which this edifice of a story has been constructed. Well, here it is (PDF format, 280kb), and there is also a Powerpoint presentation given by Professor Smith – back in November 2006.

So, to summarise: someone unconnected with the government, gave a talk nearly nine months ago in which he floated an idea; no-one in government has backed the idea; and if they did it would mean abandoning a policy that the current prime minister introduced and actively promoted for a decade as chancellor.

Should anyone take the newspaper reports seriously? I'm always willing to be proved wrong, but I wouldn't personally put any money on the story outlasting the silly season.