London4Europe is all party and non-party. There are many different ways of being "for Europe". I cannot tell you which of the positive visions of Europe that is on offer is the best. That depends on you and your politics.
A reminder of the voting system
All candidates for Change UK, Green and the Liberal Democrats are for Remain & referendum.
The second-listed Conservative candidate supports Remain and a Final Say referendum but the others do not. In May, three of the polls suggest that the Conservative might gain two seats, four forecast zero seat; half the polls show them on one seat.
Most but not all of the higher-placed Labour candidates support Remain and a referendum with varying degrees of enthusiasm, though some also strongly support Corbyn and it is not clear which would be their higher loyalty.
European party group manifestos
In the European Parliament, most MEPs sit as part of transnational European Party Groups.
The Groups also have their Spitzenkandidat - the lead candidate for the Presidency of the European Commission. The European Council should take into account which Group has the most MEPs when putting the next President forward to Parliament for majority approval.
Apart from Change UK, parties have made clear which Group they would join. You can therefore see which UK party supports the Group whose vision of Europe you like best.
UK party manifestos
Where we take a view is on whether the parties support Remain and a referendum:
Change UK, Greens and Liberal Democrats are for Remain and a referendum.
The Brexit Party, Conservatives, Labour and UKIP are for Brexit. Labour has stated that if it cannot obtain a Brexit that it has put forward that it would then seek a general election in which it would campaign for its Brexit; and that if it cannot secure a general election it would then "back the option of a public vote".
You will need to make up your own mind on this point: if you are attracted to the manifesto of the European Conservatives and Reformists (backed by the Conservative Party) or the Party of European Socialists/ Progressive Alliance of Socialists and Democrats (backed by the Labour Party) you do have to ask yourself whether a vote for that Group is really a vote "for Europe" when the UK party is seeking to take the UK out of the EU and thus ensure that UK MEPs will not be in Brussels to help to implement the programme or take responsibility for the outcome of early decisions.
Neither the Conservatives' nor Labour's election leaflet to households makes any mention of any policy they would pursue in the European Parliament. That confirms their pro-Brexit stance.
Those who wish to vote to maximise the seats in the European Parliament that are held by parties uncompromisingly pro-Europe, pro-Remain, need to ask themselves whether they should just vote for the party they prefer or whether they should vote tactically.
We have analysed the London subset of each opinion poll in a series of blogs on our website with a weekly tracker to pull results together (last week's here). We will issue our final tracker tomorrow evening and include it in the new-blogs mailing on Wednesday. All the usual caveats about polls apply even more than usual because London figures are normally a small sub-set of national polls.
We have tried to see whether there was a clear lead party amongst the Remain parties in London. The polls taken after the local government elections show the Liberal Democrats in the lead and set for one or two seats.
Support for the Greens and Change UK is running at much the same level. They are each in the running for one or zero seat. The difference between them in the London polls is too small to allow a statistically valid conclusion to be drawn. In the three large London polls, the Greens have led Change UK. In the national polls the Greens tend to lead Change UK. But the difference between the two parties is not enough to be certain, given the margin of polling error.
But with D'Hondt as this LSE blog shows the pattern of votes matters and there is no easy way to say whether a tactical voter would do better to back the largest Remain party or one of the two smaller ones that might be on the brink of winning a seat. The point is, when thinking who will win the 8th seat you may be asking whether it is better to increase say ½ of the vote of the largest Remain party or the whole of the vote of the next Remain party. You also need to consider carefully what other voters will do, including the recipients of tactical voting advice.
If interested in more concrete tactical voting advice you could sign up with Remain-Voter or Gina Miller's Remain United sites. I can offer no assessment of their competence or motivation. You can look at their explanations of their methods to see whether they have understood the complexities of tactical voting under D'Hondt.
In my view the key implication of the polls and the nature of D'Hondt is that the best voting advice is not to vote tactically but strategically: if Remain is your priority then vote for the one of the three Remain parties that best meets your idea for Europe.
I do not believe that the European Parliament elections can usefully be interpreted as a referendum on Brexit. They are however an important opportunity to vote for Europe. You will need to decide whether a vote for a pro-Brexit party can be a vote for Europe or whether only a vote for a pro-Remain party counts as such.
Like many of you, I have had to wrestle with conflicting loyalties to reach a decision. My personal conclusion is that in this vote - of all elections - I should make my cross on the ballot paper only for a party that unequivocally backs Remain.