Miliband fears he has more to lose in elections than just council seats

Meltdown in mid-term voting on 3 May would seal the fate of Labour's under-pressure leader

Normally, mid-term elections pose the biggest headache for the government of the day. But council and mayoral elections on 3 May will be widely seen as a test of Labour's progress under Ed Miliband.

Labour looks certain to make some gains – if only because it did so badly when the seats up for grabs were last fought in 2008, when Gordon Brown's government was becoming unpopular. Like all the parties, Labour is playing the low-expectations game, saying its target is to gain 350 council seats in England and 120 in Wales. Election experts say Mr Miliband should be able to count more than 600 overall gains. "Labour can make almost 300 gains simply by repeating last year's pincer movement against the Conservatives and Liberal Democrats in the metropolitan boroughs," Colin Rallings and Michael Thrasher, professors at Plymouth University, said.

Almost 5,000 seats in 181 local authorities in England, Scotland and Wales are being contested. But the highest-profile battle will be in London, where Boris Johnson, the Conservative Mayor, and Ken Livingstone, his Labour predecessor, are doing battle. London is viewed as a "Labour city" and the party did relatively well there in the 2010 general election. Mr Johnson performed strongly in the outer London boroughs when he ousted Mr Livingstone four years ago; his test will be to "get out the vote" in equal numbers in the suburbs again. Yesterday, a ComRes poll for the London Evening Standard, London Tonight and LBC showed Mr Johnson on 53 per cent and Mr Livingstone on 47 per cent.

Many eyes will also be on Glasgow, where Labour has controlled the city council since 1977 but could be ousted by Alex Salmond's Scottish National Party. A better prospect for Labour will be Birmingham, England's biggest local authority, where the prize of dislodging a Conservative-Liberal Democrat coalition would be won by gaining just five seats. Another Labour target is Bradford, but that is suddenly looking more problematic after George Galloway's surprise victory in last month's Bradford West by-election.

The Conservatives did well when the same council seats were last fought in 2008, winning 43 per cent of the votes compared to Labour's disastrous 24 per cent and the Liberal Democrats' 23 per cent.

The Liberal Democrats are braced for the loss of up to 300 of the 770 seats they are defending as Labour benefits in the North of England from Nick Clegg's decision to join the Tories in the Coalition. The Liberal Democrats will argue that the rate of losses has slowed since the ones they suffered a year ago but that may not prevent bad headlines. They are standing in fewer council seats than previously, but there may be a crumb of comfort in the small print: Mr Clegg's party hopes to do well in the 57 parliamentary seats it holds by targeting its resources.

Pressure points: May battlegrounds

The overview

Elections take place on 3 May in 36 metropolitan boroughs, 18 all-purpose unitary authorities and 74 districts councils in England, 32 councils in Scotland and 21 in Wales. Mayors will be elected in London, Liverpool and Salford. 10 areas will have a referendum on whether to have an elected Mayor – Birmingham, Bradford, Bristol, Coventry, Leeds, Manchester, Newcastle-upon-Tyne, Nottingham, Sheffield and Wakefield.

Councils to watch

Birmingham Labour should oust Conservative-Liberal coalition.

Bradford Labour needs 1 per cent swing to win control but faces late challenge from George Galloway's Respect Party.

Glasgow Alex Salmond's Scottish National Party could push Labour out for first time since 1977.

Cambridge Liberal Democrats under pressure.

Stockport Liberal Democrats may lose control of hung council.