Britain's Prince Harry is challenging a government decision that he should not receive police protection when on British soil.
Even if he covers the cost himself, his legal representatives said.
Harry and his wife Meghan quit royal duties in 2020 to forge new careers in Los Angeles.
The couple has since relied upon a private security team.
But his legal representatives said that these arrangements did not give the prince the level of protection he needed while visiting Britain.
Citing an incident in July 2021 where they said his security had been compromised whilst leaving a charity event.
"With the lack of police protection comes too great a personal risk." The statement said.
"Prince Harry hopes that his petition – after close to two years of pleas for security in the UK – will resolve this situation.
Harry's mother Princess Diana died in a car crash in 1997 while trying to escape the paparazzi.
The prince's lawyers said the government has previously dismissed two offers to pay for his police protection.
Harry sought a judicial review in September 2021, according to the statement.
His lawyers decided to make that information public due to a leak in the British press.
A government spokesperson said that the UK government's protective security system was "rigorous and proportionate," and that it was its long-standing policy not to provide detailed information on any arrangements as this could compromise individuals' security.