David Cameron has told other EU leaders that it "cannot be business as usual" in Brussels following the success of eurosceptic parties in the European elections.
The Prime Minister's spokesman said Mr Cameron had spoken to leaders including Germany's Angela Merkel and the Irish Taoiseach, Enda Kenny.
He will also hold talks tomorrow at a dinner in Brussels tomorrow evening.
"The PM has been making the point in these conversations that leaders should seize the opportunity of tomorrow's dinner to heed the views expressed at the ballot box that the EU needs to change and to show it cannot be business as usual," the spokesman added.
More top news
Very warm in the southeast tomorrow
An astronaut on the International Space Station has shared his experiences from outer space in the first Twitter chat from the craft.
Kate is now an advanced diver after passing a Professional Association of Diving Instructors (PADI) advanced open water diver qualification.