Will there be a nationalist surge in the European Parliament election?

I doubt that. They are clearly present in the political systems of practically all European countries. They will do fairly well in some cases, somewhat less well in some cases. I think the great success they might have is in Italy. The Lega Nord of deputy prime minister Salvini I think they're going to do badly, fairly badly in Germany, which is important then it remains to be seen what happens in France. The contest between Macron and LePen and Britain will be its own particular mess.

Will Theresa May's latest maneuver break the deadlock on Brexit?

I think that unfortunately is somewhat unlikely. She would make the fourth attempt to get the agreement through the House of Commons in the beginning of June. But at the moment it doesn't look like it's going nowhere. And that applies to the future of her prime ministership as well.