East Worthing and Shoreham MP Tim Loughton has been given permission for an emergency Commons debate after being issued with a police information notice.
Mr Loughton complained to Commons Speaker John Bercow after he received the notice, also known as a harassment warning notice.
In a statement, Mr Bercow told MPs the matter should be given “the precedence accorded to matters of privilege”.
He did not reveal any more details, however.
The debate will take place at around 12:30pm.
Mr Loughton has been involved in a long-running row with a constituent who accused him of racism.
In a Commons debate in March, he said his constituent had “worked tirelessly to try to make my life hell”.
Mr Loughton said the constituent had sworn at him, accused him of lying and arrogance and published “creatively doctored photographs” on his blog - including one depicting him “toting a smoking gun in a playground full of screaming, fleeing children”.
After he had responded to the constituent in an angry email that also included some swearing, Sussex Police began an investigation, interviewing the MP for 90 minutes under caution on suspicion of sending a malicious communication.
Six months later, Mr Loughton said, he was informed that no further action would be taken.
He told MPs that he planned to make a formal complaint against the force.
A police information notice may be issued where there are allegations of harassment, but does not imply that the police believe the alleged harassment has taken place.