Gordon Brown wished Nicolas Sarkozy a “speedy recovery” today after the French president was rushed to hospital after collapsing during a jog.
The Prime Minister, who gets on well with his French counterpart, sent a private message this afternoon.
Mr Sarkozy, 54, was taken by helicopter to a military hospital where he underwent tests.
The Elysee Palace said the results were normal but that doctors would keep him under observation until tomorrow.
He and Mr Brown last met at the one-day Anglo-French summit at Evian-les-Bains on July 6. They speak regularly.
A Downing Street spokesman said: “The Prime Minister has sent a private message to President Sarkozy expressing his support and wishing him a speedy recovery.”
Mr Sarkozy, who is known for his hyperactivity, had been jogging in the grounds of the Chateau of Versailles.
An Elysee statement said that the president had felt “unwell” after 45 minutes of “intense physical activity”.