The protester who disrupted this year’s Oxford v Cambridge Boat Race by swimming into the path of the crews has been jailed for six months.

Trenton Oldfield, of Myrdle Street, Shadwell, was watched by millions of television viewers as he halted the annual race on the Thames between Oxford and Cambridge universities on April 7.

He was found guilty at London’s Isleworth Crown Court last month of causing a public nuisance and returned to the same court today to be sentenced. In addition to the jail sentence he was also ordered to pay �750 costs.

Oldfield, supported in court by a throng of well-wishers, smirked as Judge Anne Molyneux passed sentence.

But he looked surprised as the jail term was handed down.

The judge said Oldfield had acted dangerously, disproportionately, had not shown what he was actually protesting against, and displayed prejudice in sabotaging the event which Oldfield regarded as elitist.

Judge Molyneux said Oldfield ruined the race for everyone.

She said: “You caused delay and disruption to it and to the members of the public who had gone to watch it and to enjoy the spectacle of top athletes competing.

“The rowers had trained for many months.

“You had no regard for the sacrifices they had made or for their rigorous training when you swam into their paths.”

Adding that Oldfield’s actions had endangered his life and those of others, the judge said: “You decided that you had the right to stop members of the public enjoying a sporting competition which they had chosen to go and watch.

“You did not have that right.

“You did nothing to address inequality by giving yourself the right to spoil the enjoyment of others.

“In doing so, you acted without regard for equality and contrary to the meaning of it.

“You made your decision to sabotage the race based on the membership or perceived membership of its participants of a group to which you took exception.

“That is prejudice.

“Every individual and group of society is entitled to respect.

“It is a necessary part of a liberal and tolerant society that no one should be targeted because of a characteristic with which another takes issue.

“Prejudice in any form is wrong.

“Your offence was planned. It was deliberate. It was disproportionate. It was dangerous.

“You have shown no regret.”