David Cameron is holding talks with the German Chancellor Angela Merkel in Berlin today - someone he needs to win over if he is to have any chance of pushing his EU reform plans through.
He is also due to meet the Polish Prime Minister today, as he wraps up his bid to renegotiate the terms of the UK's membership of the European Union with key leaders.
David Cameron said the UK and the Netherlands were "old friends and like-minded allies" as he met with Dutch prime minister Mark Rutte in The Hague.
Among the issues to be discussed will be European reform, the need for flexibility and the need to focus on growth and jobs, Mr Cameron said.
The Hague is the first of four European capitals the Prime Minister is visiting on a whirlwind tour to discuss his plans to renegotiate the terms of the UK's membership of the European Union with key leaders.
Later Mr Cameron will travel to Paris in France where he will meet with President Hollande.
David Cameron has begun a whirlwind tour of Europe to discuss his terms for renegotiating the UK's membership of the EU with key leaders.
Prime Minister plans a whistle-stop charm offensive with EU leaders this week.
Details of the In/Out referendum will be presented to Parliament in a Bill this morning.