Where the parties stand: Europe

Traditionally the most pro-European of the three main parties, the Liberal Democrats have recently tempered their enthusiasm a little, stressing their pro-reform credentials to head off Tory attacks (2008 Getty Images)

Labour

Labour will warn during the campaign that a Tory government would leave Britain isolated on the margins of Europe, putting inward investment at risk. It will talk up Gordon Brown's plan for an EU-wide, post-recession "compact for jobs and growth" to create 15 million jobs, and highlight plans for Europe to combat global warming by cutting its carbon emissions by 30 per cent by 2020 (on which some EU nations are less keen than Britain). Unlike the Tories, Labour will not say "never" to joining the euro, but there is no sign of it happening – not least because of the tensions within the eurozone in recent months. There is little difference between Labour and the Liberal Democrats on Europe, so the issue would be no barrier to co-operation in a hung parliament.

Tories

Although David Cameron dropped the Tories' pledge of a referendum on the EU's Treaty of Lisbon after it was ratified by all 27 member states, he tried to placate his party's Eurosceptics by promising a full opt-out from the charter of fundamental rights; greater protection against EU encroachment in the UK's criminal justice system; and the restoration of national control over employment legislation. All this would be easier said than done. The Tories' natural centre-right allies in Europe are sore about Cameron's decision to pull his MEPs out of the mainstream European People's Party in the European Parliament. They view him with suspicion. Cameron has kept Europe low key as Tory leader but the decibel level could increase – especially if he has a small majority, which would encourage hardline Eurosceptic Tory MPs to hold him to ransom.

Lib Dems

Traditionally the most pro-European of the three main parties, the Liberal Democrats have recently tempered their enthusiasm a little, stressing their pro-reform credentials to head off Tory attacks. They want 30 per cent of agricultural spending switched to rural development. The Liberal Democrats argue that to get the best out of Europe, Britain "must lead from the front, not snipe from the sidelines". They claim to be the only party with the vision and the confidence to stand up for a strong British role in Europe. They believe the EU is the right forum for tackling climate change, cross-border crime and problems caused by globalisation, and so would "strengthen ties" with Britain's EU partners. Europe would be a possible source of tension in the event of a minority Tory Government.