East Worthing and Shoreham MP Tim Loughton has attacked police for warning him he could be prosecuted for harassing a constituent, insisting the complainant has been leading a "vile crusade".

The Conservative MP previously told the Commons that Sussex Police spent six months investigating him for alleged racist abuse after describing ''nightmare constituent" Kieran Francis as ''unkempt''.

Mr Loughton said his constituent stepped up an "onslaught of vile abuse", mainly against him, including doctoring photographs of his children taken from social media sites plus urging him to commit suicide, after he raised the issue during a Commons debate in March.

During this debate the one-time education minister said he was "sacking Mr Francis as my constituent", adding that his staff had been instructed to put the phone down on him.

Mr Loughton said he planned to inform Mr Francis of this information in a letter but instead sent a complete Hansard record which included the March 13 debate.

But the MP said today that this action, which he took following advice from a Parliament clerk and believed would be covered by parliamentary privilege, resulted in him receiving a police information notice (Pin) from Sussex Police.

The Pin warned that this action had caused "alarm and distress" to the ex-constituent and warned he would be liable to arrest and prosecution if that kind of behaviour continued, according to Mr Loughton.

The Tory told the Commons he believed Sussex Police's actions represented a "clear breach" of parliamentary privilege, which grants certain legal immunities for members to allow them to perform their duties without interference from outside the House.

Mr Loughton said: "If this goes unchecked, any constituent with a grudge against his or her member of Parliament could claim harassment.

"Any MP exposing any dodgy organisation in Parliament could find themselves being questioned by the police and... being given advice as to how to do our job.

"Indeed, Abu Hamza may well have a case against (Home Secretary Theresa
May) for being rightly beastly about him in Parliament and find herself on the receiving end of a police information notice."

Mr Loughton's motion for the Pin to be referred to the Committee of Privileges was passed unopposed in the Commons.

Moving the motion, Mr Loughton said he had no communication with his ex-constituent since sending the Hansard record while he claimed Mr Francis had "stepped up an onslaught of vile abuse", which included targeting the leader and chairman of Adur District Council, among others.

Mr Loughton said: "Yesterday he (Mr Francis) was abusing the organisers of Worthing Mental Health Awareness Week, which I have launched, and to date he has posted on his blog or sent tweets to or about me and my council colleagues on well over 200 occasions.

"Many come under the heading of political abuse which, however offensive that is, we all know it is part of our job.

"However, what is not part of that job is they have included doctored photographs of my children taken from their social media sites - what a man in his 40s is doing trawling the social media sites of teenage girls I do not know.

"They were eventually taken down but he then attempted blackmail - to put them up again - against me unless I comply with his demands.

"He's posted doctored pictures of the council leader's young children with Nazi insignia.

"He has posted vile contorted accounts of my parents' divorce, forged tweets, posted references to my neighbours, photographs of my home, most recently a direct tweet urging me to commit suicide, along with assorted lies, made-up stories and pure fantasy."

Mr Loughton said despite making complaints to the police, Mr Francis had been arrested once and no charges were brought against him.

He said: "The police have failed to secure any charges and he carries on harassing, bullying, stalking, trolling and abusing me, my family and colleagues."

On September 4, Mr Loughton said a Pin notice was served against him.

He said: "The notice stated the police had received an allegation of harassment against me by the aforementioned constituent, making me aware if the kind of behaviour described were to continue, then I would be liable to arrest and prosecution.

"And the specific single incident behaviour which gave rise to this Pin was the act of sending a copy of Hansard to my constituent.

"Apparently this had caused my ex-constituent alarm and distress. That came as a surprise to me and various others, particularly given on his blog on March 14 that ex-constituent had described how he had watched my adjournment (debate) on television with great amusement.

"Apparently Hansard is a cause of alarm and distress. Our deliberations are a potent weapon of abuse if you work for Sussex Police.

"For good measure, the leader of Adur council, the chairman of Adur council and his ward councillor were also all issued with Pins for supposed harassment as well as the constituent himself, although it has clearly only fuelled his vile crusade even more.

"Apparently a gold group led by an assistant chief constable, Robin Merrett, met on July 3 to approve these Pin notices at the highest level.

"Two months later they were served on me and my councillor colleagues without me knowing that a complaint of harassment had even been made against me, nor that I was under any investigation for it, in clear breach of the police's own guidance, which state I should be given an opportunity to be interviewed to account for my actions to show that they were reasonable and lawful. No such interview took place."

Mr Loughton said there was no way to appeal against a Pin and it remains on file for at least 12 months.

He added that Detective Chief Inspector David Wardley-Wilkins had also offered him instructions about how he should correspond with constituents without risking a Pin.

Mr Loughton said: "Police telling us how to do our job. The chief constable, who has been copied in to all these events, has been content to waste taxpayers' resources on this nonsense while senior management of his force are brought into disrepute and he has clearly lost the plot when it comes to distinguishing between the victim and the perpetrator."

In a statement, Sussex Police said the matter is related to an investigation into a series of allegations and counter allegations "where all parties have in turn been considered as victims and suspects".

Assistant Chief Constable Robin Merrett said: "We have attempted to mediate between all of the parties involved in this incident for some time, but some have declined to engage in this process and our attempts to do so have not been successful.

"We did not wish to criminalise anyone, but it became apparent that the issue was not going to be resolved among those concerned and that some form of action was necessary in order to prevent it escalating further.

"After much consideration and independent scrutiny, the decision was taken to bring matters to a conclusion by issuing Pins  to all of the parties involved. However, it appears that Mr Loughton does not consider the matter closed.

"In his speech Mr Loughton focused in particular on the supply of the Hansard record to suggest that Sussex Police has interfered with the parliamentary process. The person who received the Hansard report believed it to be a continuation of harassment against him and subsequently reported it to us.

"We would never seek to interfere with parliamentary processes or privilege, but I strongly support actions taken by the force, which have been subject to independent legal scrutiny. We will of course await the views of the Committee of Privileges before commenting further."