Centre-right parties made major gains in this weekend's European Parliament elections, while far-right parties in Britain and the Netherlands also made advances largely at the expense of the left.
The European Union said centre-right parties were expected to take the most seats — 267 — in the 736-member Parliament.
Centre-left parties were headed for 159 seats. The remainder was expected to go to smaller groupings.
In Britain, the Conservatives captured the most seats, while the vote secured the first ever victories for the anti-immigration British National Party.
The results are viewed as a disaster for Labour, the country's governing party, and its embattled leader, Prime Minister Gordon Brown, the CBC's Tom Parry reported Monday from London.
Brown, rocked by a series of resignations from his cabinet last week, is already under pressure to step down over a scandal in Britain's Parliament over the expense claims of MPs.
On Monday, Brown's woes deepened with the resignation of his environment minister, Jane Kennedy, who said she could not continue to support him as leader.
Brown was due to address Labour MPs later in the day in a meeting that some observers have stated could determine his fate as prime minister and head of the party.
Labour took only 15 per cent of the vote, dropping it to third place behind the Conservatives and the UK Independence Party, which wants to pull Britain out of the European Union.
The BNP, which wants to halt all immigration to Britain and offer incentives to newcomers already living here to go home, is sending two representatives to Brussels.
British lawmakers said the far right's advance was a reflection of anger over immigration issues and soaring unemployment from the recession.
European elections are often seen as a chance to cast a protest vote, said Simon Hicks, a specialist in European politics at the London School of Economics.
"In general, we see voters turning away from mainstream parties in European elections, partly out of protest, partly as a chance to express their disaffection with mainstream politics," Hicks told CBC News.
"Sometimes, this goes to the right, but in other cases, it goes to the left."
Labour Health Secretary Andy Burnham called the BNP's result "a two-fingered salute" to the country's mainstream parties.
In the Netherlands, the anti-Islamic Freedom Party won four seats, while far-right parties also made gains in Austria and Hungary.
Voters angry over poor economic conditions and political scandals punished ruling parties of both stripes in Greece, Austria, Spain, Britain, Bulgaria, Ireland, Hungary and the tiny island of Malta.
Fringe parties did well in part because few people turned out to vote. Just over 40 per cent of eligible voters cast ballots in the European elections. In Britain, turnout was even lower.
The low turnout was also a discouraging sign for EU officials hoping Irish voters will approve stronger powers for the EU in a fall referendum.
Ireland is the only one of the 27 EU nations that must still ratify the reforms.