Labour is in danger of “wipeout” in the June 4 local elections, losing up to half the 500 seats and all four councils it is defending, an analysis for The Sunday Times shows.

The party will go into next month’s local elections in third place behind the Conservatives and Liberal Democrats, according to the study by Professors Colin Rallings and Michael Thrasher of the Elections Centre, University of Plymouth.

Next month’s local elections will see voting in 34 local authorities in England, mainly outside the big cities, alongside the nationwide European parliament poll. There are also three votes for directly elected mayors, in Doncaster, Hartlepool and North Tyneside.

These elections were last contested on general election day in 2005, since which time there has been a double-figure opinion poll swing from Labour to the Tories.

Rallings and Thrasher compile an alternative measure of public opinion, based on actual voting in council by-elections. The latest such survey puts the Tories on a national equivalent vote share of 40%, up nine points on four years ago. The Liberal Democrats are on 27%, the same as in 2005, with Labour down nine points on 25%.

“If these figures are reflected in the actual votes cast in June, the Tories would gain over 300 seats with Labour down by nearly 250,” Rallings and Thrasher write in their analysis.

“The Lib Dems would also lose out as many voters switch directly from Labour.

“On that basis Labour will post its worst county results since 1977. Then, as now, an unpopular Labour government faced voters reeling from the impact of recession.”

A wipeout in the local elections would indicate that Labour is haemorrhaging support in its nonmetropolitan heartland. Derbyshire, Nottinghamshire and Staffordshire have been Labour-controlled since 1981, with Labour briefly losing its overall majority in Lancashire in 1985. All would slip from its grasp on modest swings to the Tories of between 1% and 5%.

Party managers will be trying to dampen expectations ahead of the elections but the story is clear, according to Rallings and Thrasher.

“The Tories may be at a historic high water mark across local government, but there is room for improvement in this particular election cycle,” they write. “Nothing less than gains well into three figures and a share of the national vote above 40% will justify the claim that David Cameron is on his way to Downing Street.”

A strong Tory showing, however, would not just hit Labour. The Tories would take Devon on a 3% swing away from the Liberal Democrats; in Somerset a swing of just 2% since 2005 is needed.

Rallings and Thrasher think that minor parties such as the British National party, the Green party and the UK Independence party will do less well in local elections than in the European vote.

“Voters opt for the more traditional parties when tangible local issues and control of their council tax levying authority is at stake,” they say.

The Conservatives require a 6.9% general election swing to secure a Commons majority so the June 4 results will be studied closely, with some areas closely matching parliamentary constituencies.

Places such as Carlisle, where Labour has a notional majority of 13%, Hyndburn (14%) and Warwickshire North (15%) will provide key indications. For the Liberal Democrats, Cheltenham, where the party has a 1% notional majority over the Tories, the newly created Chippenham constituency (5%) and Newton Abbot (10%) will be closely monitored.

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