National Front leader Marine Le Pen called for the dissolution of the French National Assembly after exit polls showed her anti-immigrant, Eurosceptic party winning European Parliament elections in France.
"What else can the president do after such a rejection?" Ms Le Pen said.
"It is unacceptable that the assembly should be so unrepresentative of the French people."
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Rain will spread eastwards across southern areas tonight. Clear and frosty in the north.
Political leaders will go head-to-head at ITV's studios in MediaCityUK in Salford, ITV has confirmed, as the set for the event is unveiled.
More than 100 people claiming to represent working people across Britain have signed a letter backing Labour in the general election.