Labour last night rejected claims Jeremy Corbyn's health could torpedo his bid for No10.
The Times claimed senior civil servants feared he has become “too frail and is losing his memory” and maybe forced to step down as Labour leader.
But a party spokesman said: " Jeremy Corbyn leads an active life, running and cycling regularly, and is in good health.
“Reports to the contrary are scurrilous and a transparent attempt to undermine Labour's efforts to redistribute wealth and power from the few to the many."
Mr Corbyn has been receiving treatment for a muscle weakness in his right eye, the party has previously said.
The report claimed civil servants believe Corbyn is being "propped up" by his advisers.
One civil servant said: "There is a real worry that the Labour leader isn't up to the job physically or mentally but is being propped up by those around him.
"There's growing concern that he's too frail and is losing his memory. He's not in charge of his own party."
The claims come amid the possibility a general election could be called over Brexit .
But Labout have confirmed Corbyn has a very active lifestyle and runs several times per week.
Back in March, Mr Corbyn's spokesman confirmed the Labour leader is "very active, both on behalf of the party and in his own personal life."
The spokesman confirmed Mr Corbyn is a "very keen cyclist and a very keen runner".
It's understood Mr Corbyn runs between 5 and 7km several times a week, as well as cycling and frequently working out at an outdoor gym.
