It was the turn of the Liberal lead candidate (ALDE) for the EU top job Guy Verhofstadt to take the hot seat on Raw Questions.
A staunch federalist, he defended his ideas on more Europe.
"(The) United States of Europe is a way to organise common action on the European level by recognising, by guaranteeing the autonomy of member state.
"I'm against a European superstate, I don't want a system where everything is decided by Brussels here next door at the European Commission."
The former Belgian prime minister said the rise of populism was down to European failures — specifically when it came to crises, like migration: "It's because of a lack of EU policies. There is no EU border coast guard. There is no common European asylum system.
"There is thirdly not a European economic migration system giving people the possibility to come to Europe in a legal way.
"My first priority (is) to tackle the tragedies in the Mediterranean by establishing these three building blocks."
And on green ambitions, a question from a youth climate strike leader Anuna De Wever about what the Liberals would do to fight the climate crisis.
"The first is to (make) climate change a condition to make deals with Europe... In negotiations with China and America, we have to use that weight, to say to Trump, if you want a free trade agreement then you have to sign up to (the) Paris agreement."
And the Brexit coordinator for the European Parliament, Verhofstadt, believes his Liberal allies in Britain will have a decisive role.
"What I think will happen is a big fight in these elections, and I never was in favour of these elections, a big fight between on the one hand the Brexit party, and on the other hand the Liberal Democrat party as the most pro-European party in Britain, let's see what will happen, that's democracy."
In a final nod to his pro-EU personality, when asked whether he preferred wine over beer, a European choice won over the national tipple of his native Belgium.
"I think that wine in Europe is civilisation — it has been in the whole of the Roman Empire — wine-drinking countries."
Tuesday is the turn of the European Conservatives and Reformist candidate, Jan Zahradil. Tune in from 21 pm CEST.