The Tory candidates who have come forward so far to stand as Police and Crime Commissioners (PCCs) have been "a massive disappointment" for Number 10, with more than three quarters of them either former or current members of the police authorities that are being scrapped, The Huffington Post UK understands.

A senior Tory source has also told HuffPost UK that Downing Street's wish that Tory candidates should go through an "open primary" process has angered many constituency associations, who are expected to foot the bill for the hustings.

Ministers and MPs are said to be trying to distance themselves from a policy which could initially see desperately low turnouts and unsuitable people standing on party tickets. "This is one of those Steve Hilton, David Cameron, blue skies ideas," said the Conservative Campaign Headquarters (CCHQ) source.

David Cameron's inner circle are now privately worried about a severe lack of decent and distinctive candidates standing for the Conservative party in the elections for PCCs. Their introduction was a flagship policy in the Tory manifesto at the 2010 election, but it's hard to find any Tory MPS - particularly on the backbenches - who are wildly enthusiastic about it.

Around 220 people have registered on the Conservatives' website to stand as police commissioner so far, but the vast majority of these have experience on Police Authorities, the current bodies across England and Wales which scrutinise police chief constables.

Many Tories now believe that the police commissioners and the Police and Crime Panels they appoint will end up being very similar in make-up to the Police Authorities they are replacing.

A CCHQ source - close to Theresa May and involved with the open primaries process - says in some areas the better candidates on long-lists are unlikely to be selected, because they won't be "demagogic" enough to have mass appeal.

"People are saying that standing for election, your mind has to work in a particular way," Huffpost UK was told. "For the better people for this job, standing in hustings and knocking on doors is not their thing."

Another issue has been on pay. Some high-fliers who initially expressed an interest in standing cooled off when they discovered the salary range, between £60,000 and £100,000 depending on the size of the police force.

The former Army officer Tim Collins, who had been considering standing as a PCC in Kent for the Tories, is now thought to have withdrawn his candidacy. He had believed that being a PCC would be a part-time job, but the intention is that PCCs will work full-time and not expected to hold any other position.

The inaugural elections for PCCs will take place on 15 November across England and Wales but not in London, which has separate policing arrangements. Many Tory MPs are fearful that holding the elections outside of British Summer Time in the depths of autumn will lead to low turnouts.

The elections were due to be held in May of this year, on the same day as local elections, but this was pushed back by the government last year, at a cost of £25m to the taxpayer.

Our source says that the delay was caused by a lack of enthusiasm by Theresa May towards the policy, meaning it was not made a priority within the Home Office in the first few months of the coalition, and as such the law to enact the new regime was delayed.

May has always spoken in favour of elected police commissioners, but is said to be "lukewarm" towards them behind the scenes.

"Fewer than a handful of Tory MPs really back them," a backbencher told HuffPost UK, adding that many Tories were resigned to never gaining control of the positions in Merseyside, Greater Manchester or the West Midlands.

"Quite a few Tory MPs say Labour police commissioners will build a power base as a stepping stone to Parliament, or impose Labour-style policing at odds with a Tory home secretary," HuffPost UK was told.

Labour already has one potential high-profile candidate for PCC, in the form of Lord Prescott, who is proposing to stand in Humberside.

Not all Tory PCC candidates will be selected by open primary - some will be chosen only by party members. The expectation is that all the Tory candidates will be finalised in May.

Each Conservative association is expected to contribute £5,000 towards the selection and campaign, something many are said to be annoyed about, at a time when local party coffers are low because of declining membership.