The European election results from Wales are expected on Sunday night
On the eve of the European elections all the parties in Wales are making a final effort to get their vote out.
Labour said a strong Labour team in Brussels was needed during recession, Lib Dems emphasised a "pragmatic vision of Wales stronger... with Europe."
Plaid Cymru called for a vote for a "step change" in Welsh politics and Conservatives promoted their promise to hold a referendum on the Lisbon Treaty.
Seven other parties are also contesting the four Welsh seats on Thursday.
In the previous election, in 2004, Labour won two of the seats, with the Conservatives and Plaid Cymru one each.
In a joint statement, Welsh Labour leader and First Minister Rhodri Morgan and Welsh Secretary Paul Murphy said there was "a lot at stake for Wales on Thursday".
"Because so many decisions taken in Europe can help create jobs in Wales, we need a united 'Team Wales' to secure maximum assistance from Europe to help us keep and create more jobs in Wales."
They continued: "During a recession it is more important than ever for us to get a strong Labour team in Brussels to help our economy, improve our environment, raise our skills levels and protect our rights in employment.
"It is at times like this that people turn to Labour because they know that Labour in Wales, Labour in Westminster and Labour in Europe will all work together to help communities, families, businesses and individuals right across Wales to secure a brighter future."
Highlighting their promise to hold a referendum on the Lisbon Treaty, the Conservatives' lead candidate Kay Swinburne said: "Gordon Brown promised to give the British people a say on the EU constitution by holding a referendum.
"He has broken that promise - the Lisbon Treaty is the constitution under another name.
"The Prime Minister's refusal to hold this referendum is nothing more than an act of political dishonesty.
"That's why every Welsh Conservative vote tomorrow is a vote to put pressure on Labour and Gordon Brown to hold this vote," Dr Swinburne added.
Plaid Cymru is to return to Carmarthen town centre on Wednesday, the scene of Gwynfor Evans' historic election victory in 1966, when he became his party's first MP.
Lead candidate Jill Evans said: "It is up to the people of Wales whether they want to vote for more of the same Labour and Tory under-achieving or whether it is now time for another step change in Welsh politics.
"The Welsh people have an opportunity to put Plaid ahead of Labour in a national election for the first time ever.
"I urge them to take that chance and show the London parties that their agenda is simply not good enough," Ms Evans added.
'Difficult to predict'
Welsh Liberal Democrat leader Kirsty Williams said her party had "knocked on more doors, listened to more voters and delivered more leaflets than ever before" in a European election.
She said the party had a "good chance" of winning its first Welsh European seat but "it's incredibly difficult to predict what will happen on Thursday".
Ms Williams said the Lib Dems had been "building relationships with communities and organisations across Wales that will stand the test of time" during the campaign.
She added that her party had "engaged with voters' frustration" over expenses and they were glad to have a real debate...with a party that's always campaigned for reform and has a positive but pragmatic vision of Wales stronger together with Europe".
Seven other parties have candidates standing for Welsh seats in the poll.
They are the British National Party, Christian Party, Jury Team, No2EU Yes2democracy, the Green Party, Socialist Labour Party and the UK Independence Party.
Polling stations will be open throughout the UK between 0700 and 2200 BST on Thursday. Most of the rest of Europe votes on Sunday, and no results will be announced before then. The Welsh results, along with many others, are expected on Sunday night.