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
Rain will affect many northern areas at first, pushing further south through the day.
Train operating companies are failing to properly inform passengers about their rights, according to Which?
The average house price in a UK city has surged by nearly a third over the last five years, a shocking report has found.