Police officers who have had affairs or are guilty of financial improprieties could be barred from promotion to chief constable under new measures designed to strengthen the integrity of the force.

In a move that is likely to heighten existing tensions between police and ministers, Home Secretary Theresa May is expected to announce on Tuesday 12 February a range of new measures to raise the standards of police conduct.

The 'integrity charter' will compel each of Britain's 134,000 officers to register any gifts they receive publicly and declare any second jobs they have, in moves designed to reduce the likelihood of officers being bought or bribed to secure favours.

It is estimated that 20,000 officers currently have second jobs.

A new 'code of ethics' will demand officers demonstrate 'honesty and truthfulness' and be prepared to act as whistleblowers if they become aware of misconduct in the force.

The review comes after a series of high profile cases that have damaged the force's reputation, including the Hillsborough disaster, in which officers attempted to shift the blame for the deaths of scores of spectators on to football fans, and the recent 'Plebgate' row, where officers lied that government chief whip Andrew Mitchell had branded police officers 'plebs' in an altercation.

May will announce plans for the new College of Policing to revise vetting procedures for officers wishing to be considered for senior positions, which will mean sexual harassment allegations and details of affairs will have to be taken into account in order to reduce the risk of police chiefs being subject to blackmail.

Chief constables will also have to publish details of their expenses online.

In recent months 11 former or serving senior officers have been investigated for misconduct. They include the chief constable of Cleveland Police Sean Price, who was sacked, and Sir Norman Bettison, who resigned after criticism in the wake of the Hillsborough inquiry. All deny wrongdoing.

In the announcement, May will also reveal plans to beef up the Independent Police Complaints Commission, which has been criticised as weak and ineffectual.

Earlier this year, May came under fire from police after she announced plans to allow senior foreign military and police officers, such as government adviser and former New York police chief Bill Bratton, to take up chief constable positions in the UK.

Mike Cunningham, chief constable of Staffordshire police, said: "The overwhelming majority of all those who work in policing, including those who lead the service, work tirelessly to serve their communities with commitment and integrity."