In London, where all the council seats are being contested, the prospects for the May elections are potentially grim. On their present national poll ratings, the Tories could lose as many as one in three of their seats and lose control of at least seven councils. Another council, Wandsworth, would be on a knife- edge. The party can be confident of retaining control only in three councils: Bromley, Kensington/Chelsea and Westminster. They would be left with about 450 out of around 1,900 seats in the capital - easily their worst position since the London boroughs assumed their present form in the 1960s.
In Scotland, too, the Government is facing disaster. On their present opinion poll form, the Tories could be reduced for the first time to the fourth largest party - behind Labour, the Liberal Democrats and the Nationalists - in numbers of seats held on Scottish regional councils.
And, in the European Parliament, they are on course to lose 19 of their 32 seats. They would be left without a single seat north of Cambridgeshire and the losers would include Edwina Currie, who intends to stand in Bedfordshire and Milton Keynes. The Tories would end up with 15 out of 84 UK seats at Strasbourg, because UK representation has been increased by six.
Outside London, however, the Tory prospects for the May local elections are not nearly as bad. One-third of the seats in all the English metropolitan districts and about 120 shire districts are at stake. The Tories did so badly when these seats were last fought in 1990 that, even on their present poll ratings, they cannot do much worse. They could lose a dozen of the 100 seats they are defending in the metropolitan districts and about 50 out of 400 in the shire districts. Only one council - Stratford-on-Avon - would fall.
Yet the Canada factor remains a threat. For example, if the Liberal Democrats did better than average in the South-west, as some polls suggest they could, Tory representation in the European Parliament could be down to single figures. The biggest nightmare for Mr Major would be a repeat of the voting patterns in last year's county council elections, when Tory support fell twice as much in the middle-class wards the party was defending as in the typical working- class ward. With the opposition vote also sorting itself out - the Liberal Democrats did best in the South, Labour in the North - the result was dramatic. The Tories won over 350,000 more votes than Labour but nearly 200 fewer seats. If the same happens in this year's local elections, the Tory losses in the English provinces alone could be more than 100.
Yet a disaster for the Prime Minister is far from certain. With a bit of luck, his supporters could even present the spring and summer elections as a triumph. Suppose the Tories achieved a modest recovery between now and May - to a rating of a little more than 33 per cent perhaps - while Labour fell to little more than 40 per cent from its present rating of around 47 per cent. The Tories could then make gains outside London. They need just a 3 per cent swing from 1990 to win control of Wolverhampton and Dudley or deny Labour control of Bradford. Four per cent and Derby falls into their lap. Five per cent and they get Birmingham.
Within London the Tory losses could be kept down to just two or three councils. In the June elections, the Tories could win 30 Euro-seats - well short of anything that could be described as a disaster, much less a Canada-style rout.
Is this jump from the opinion poll ratings of the past nine months at all feasible? While the Tories, in recent years, have usually performed roughly as well as their current opinion poll ratings in local or European elections, Labour has consistently failed to do so. At the ballot-box, Labour has failed to break the 40 per cent barrier for more than 10 years.
So a Tory electoral disaster is not inevitable. Mr Major's pass mark for his spring test may be no more than 33 per cent. Difficult, but not impossible. But the easier the test, the more difficult it is to explain away failure. If the headlines after the May local elections are 'Tories suffer heavy losses', the message will be unambiguous. The party will be in its deepest trouble ever, worse than at the height of the national revolt against the poll tax. That ended Margaret Thatcher's leadership; it is hard to believe that disaster in the elections this spring would not end John Major's.
The author is senior lecturer in politics at Strathclyde University.