It's the first day of the polls for the European elections, and the first countries to start voting are the UK and the Netherlands.
The election debate in the UK hasn't had much cross-over with the debates in other countries. The debate been the Europarty candidates for Commission President were shown, but only on the BBC Parliament channel so they didn't get wide coverage. The tone of the election is very much a pro- or anti-UKIP one. UKIP has been rising in popularity despite candidates and even the leader, Nigel Farage, getting themselves into hot water and despite the constant attacks of the other parties.
The Liberal Democrats are expected to lose a lot of support as they are now a party of government (they are the junior party in the Conservative-Lib Dem coalition) and are no longer very attractive for the protect vote. Nick Clegg, the Lib Dem leader, has set the party up as the "Party of In", and has taken on Nigel Farage in two debates (which Farage is widely considered to have won). The Conservatives are expecting a hit as the senior government party (they were in opposition during the last election) that's pursuing austerity in power, as well as losing Euroskeptic votes on the right to UKIP.
Labour is expected to win seats as an opposition party, but expectations are muted due to the UKIP surge. The European elections are being portrayed as a protest vote against the established parties before the run up to the 2015 general election, so poorer than expected showings for the main parties probably won't be as damaging as they might have been in past elections. The Greens are confident that they will improve their polling performance this year, but since the polling data tends to lump them in with others, I don't know what the generally predicted numbers are. The far-right British National Party will probably lose the two seats that it controversially won last time around.
Current polls: Sun/YouGov poll [BBC group of polls]:
Conservatives: 23% [31-33%]
Labour: 27% [35-38%]
Liberal Democrats: 10% [8-13%]
Greens: 8% [?]
The Netherlands last had a general election in 2012 when a VVD-PvdA (Liberals [economically right-wing] and the Labour party] grand coalition government was elected. That election had been caused by Geert Wilders' populist PVV withdrawing its support for the government (they supported the minority government in parliament but weren't part of it). In the general election the PVV lost support due to this, but now that they're not connected to the government their support has risen again.
The PVV have made common cause with the Front National in France, forming an anti-EU alliance against the "monster in Brussels".
The Prime Minister, VVD's Mark Rutte, came out just yesterday with the statement that the EU should stick to 5 key areas: the internal market, free trade, cutting red tape, combating labour market abuse and making a single energy market. The move might be intended to win back support from right-wing voters, but announcing it the day before the election is an odd decision and it may not have much of an impact.
The PvdA is in a tough position. It ran against the VVD in the last election and has made compromises as part of the government. In the general election it faced tough competition from the Socialist Party, which was very popular early on in the campaign. Now the Socialist Party is doing well in the polls and looks like it's on course to beat the PvdA.
D66, a left-liberal party is performing strongly in the polls at the moment. D66 has one of the most well-known MEPs, Sophie In't Veld, who has a strong position on privacy issues. In some polls D66 is leading.
The Dutch political party landscape is varied and it made up of a lot of small parties who will be in the running for some seats. It is unlikely that even the party with the biggest percentage of the vote will get more than 6 seats.
Currently the polls stand at (could have changed if there are more recent polls I haven't seen):
VVD (right-wing liberals): 12-16%
SP (Socialist Party): 10-12%
CDA (Christian Democrats - the big winners at the last elections): around 11%
CU-SGP (Christian Union-Reformed Political Party): 8-9.5%
GL (Groen-Links/Green-Left): 5-6%
PvdD (Party for the Animals [animals' rights party]: 1-2%