An intruder who broke into the Houses of Parliament told staff he was 'visiting Prince Andrew and Prince Charles' when he was discovered, a court heard.

Trespasser Devon Dorrall dodged round-the-clock guards and armed police to sneak into the heart of the London estate undetected at lunchtime on November 30 last year.

He was found sitting on a chair in the Mess area of the House of Lords - an incident not disclosed by authorities at the time.

He told staff he was being escorted by Prince Harry when he was challenged about his presence.

The 23-year-old from Tilehurst in Reading was charged with trespass on a protected site. He was on bail at the time for throwing glass bottles at a bar in Reading town centre two days earlier.

He is due to be sentenced in six months' time after Chief Magistrate Paul Goldspring deferred the hearing at Westminster Magistrates' Court.

The judge told Dorrall he was minded to impose a non-custodial sentence provided the defendant engages with the Government's anti-terror programme and mental health services, and commits no further offences.

The court heard he had previously been referred to Prevent having made a bomb hoax around ten years ago.

He had also 'made comments about Boris Johnson and Nigel Farage,' the Chief Magistrate said, although there were no further details mentioned in court.

Prosecutor Malachy Pakenham said a heating engineer on the estate spotted Dorrall wearing a visitor's badge, but was unaccompanied.

He said: 'The defendant said he was (a victim of crime) and he was with Prince Harry. Prince Harry was nowhere to be seen.'

The engineer contacted police who arrived on the scene within two minutes, but Dorrall refused to properly engage with them and was seen to be staring 'in a threatening manner', the court heard.

Mr Pakenham said Dorrall then claimed to have entered Parliament the previous day, and had been able to wander alone and undetected since then - something disputed by the Crown.

He said: 'The police officer asked him some questions and the defendant said he had come to the estate to visit Prince Andrew and Prince Charles, the Royal family. He also said he lived in the Palace of Westminster.'

The court previously heard that medical reports suggested Dorrall was suffering a psychotic episode at the time, but it was 'more likely than not' that this followed the consumption of illegal drugs.

The court heard he had no relevant convictions.

Defence counsel Yasmin Eshaghian said Dorrall 'probably doesn't understand' his motivations for the incident. 

He was released on bail to be sentenced for trespass and smashing two windows at Be At One.

Sources told this newspaper, which first revealed the remarkable security breach, that the alleged intruder gained access by climbing over the roof of the Parliamentary Education Centre at the southern end of the palace.

Yet neither Scotland Yard nor the Parliamentary authorities announced the security breach publicly or alerted all members and staff to it, raising suspicions that they wanted to avoid the embarrassing publicity.

It came just months after the new fence – branded 'hideous' by peers – was put up along the boundary of the parliamentary estate while £10million was spent on a door that did not work.

One insider told this newspaper: 'After £10m on a door and other works which is still not fully operational, at least £4.5m on a high security fence it is a complete embarrassment that someone can just climb in and get so deep into the site before being stopped by a workman.

'No wonder it has been kept secret.'

In response to inquiries from this newspaper, a House of Lords spokesman said: 'We can confirm a member of the public was arrested for trespassing on the Parliamentary Estate on Sunday 30 November.

'This is being dealt with by the Metropolitan Police. Following the incident security arrangements were urgently reviewed and enhanced measures put in place.'

Asked if members of the Lords were told, the spokesman said: 'As is normal practice the relevant domestic committees and office holders in the House were informed about the incident.'

A spokesman for the Metropolitan Police confirmed: 'Police were called at 13:04hrs on Sunday, 30 November to the Palace of Westminster where they arrested an intruder.

'He did not come into contact with any staff or members of the House.'

It was the latest in a series of major alleged security breaches to hit Parliament.

In November two men were arrested after a phone was planted in the Commons chamber in an apparent attempt to play 'sex noises' during Prime Minister's Questions.

In March a man spent 16 hours perched on a ledge after climbing up the clock tower of Big Ben to unfurl a Palestinian flag.

Four years ago a man scaled the fence near the Carriage Gates entrance to Parliament and got into New Palace Yard, despite security being strengthened after PC Keith Palmer was stabbed to death by terrorist Khalid Masood in 2017.