FRANCE: National Front. Leader Marine Le Pen won nearly 18 percent of vote in April's first round of presidential elections. Eyeing seats in June parliamentary elections.
GREECE: Golden Dawn. A neo-Nazi party that is one of Europe's most extreme. Prospering with pain of austerity program. Could take a dozen seats in May 6 parliamentary election.
NETHERLANDS: Freedom Party. Led by Geert Wilders, it's third-largest in parliament, brought down minority government by withdrawing support.
AUSTRIA: Freedom Party, 34 of 183 seats in parliament, second-strongest party in opinion polls.
BRITAIN: British National Party. Membership restricted to "indigenous British people." Ten local councillors, down from 50 in 2008.
GERMANY: NPD. In 2 of 16 state legislators but no seats in national parliament. Support base in former Communist east German states where unemployment, discontent high.
NORWAY: Progress Party in Norway. Holds 41 of 169 seats in parliament. Norway's biggest opposition party. More moderate than many European counterparts.
DENMARK: Danish People's Party. Third largest party. Was kingmaker in parliament for 10 years. Pushed Denmark to adopt some of Europe's strictest immigration laws.
SWEDEN: Sweden Democrats. Entered parliament in 2010 with 19 of 349 seats but no major impact on legislation.
FINLAND: The Finns. Won 19 percent of parliamentary election votes in 2011—up from 4 percent four years earlier.
HUNGARY: Jobbik. Won nearly 17 percent of 2010 vote. One of two leading opposition parties. Also, conservative Fidesz party of Prime Minister Viktor Orban passing laws restricting civil rights, basic freedoms that go against its EU membership.