Police forces who fail to bulk-buy their uniforms, handcuffs, boots and other standard equipment in collaboration with other forces should face financial penalties, MPs on the Westminster spending watchdog have warned.

The Public Accounts Committee (PAC) says police forces are still wasting millions by not buying jointly in bulk. They say the price paid for basic kit such as standard-issue boots has varied from £25 to £114, and from £14 to £43 for handcuffs.

Margaret Hodge, the PAC's chair, said this was the case even where the items being bought were identical: "It cannot be right that prices paid for the same type of high-visibility jacket varied by as much as 33%. Forces can make big savings through bulk-buying of items, but have been unable to agree on the most simple things, like how many pockets they should have on their uniforms," she said.

The Home Office has put in place a major drive to persuade forces to collaborate over the way they spend their £1.7bn procurement budget each year, but it has failed to make much headway.

An investigation by the National Audit Office found there was a 400% difference in the prices paid for high-vis jackets, with the cheapest at £20 and the most expensive at £100. The auditors found that forces had more than 20 different specifications for the jackets they were buying and even when they were the same type there could be a 33% difference in price.

They also found that 16 different types of riot shields were being bought with the prices paid ranging from £31 to £136. There were also 16 different specifications of body armour with the price paid varying from £203 to £410.

A dedicated online "hub" to buy police products was set up by the Home Office in the expectation that all 43 forces in England and Wales would be using it by June 2012. But so far fewer than half of the forces have used it. The MPs say that only 2% of items have been bought through the hub compared with the Home Office's target of 80% by the next general election in 2015.

The election of police and crime commissioners last November also complicated the situation as they are responsible for local value for money and have the power to opt out of national arrangements for buying uniforms and kit.

Hodge said: "We recognise that police and crime commissioners have authority over local spending but, as the Home Office remains accountable for public money voted by parliament, it cannot step back from value-for-money issues."

"The Home Office cannot persuade enough individual forces to co-operate with its attempts to introduce more centralised procurement, in part because forces are sceptical about the commercial competence of the procurement officers working at the centre."

The MPs say the Home Office accounting officer should use financial incentives and penalties to ensure forces collaborate and secure bigger savings through bulk-buying.

The committee also recommends that full details of what each force spends on uniforms and kit should be published so that the public can make clear comparisons between what forces are paying.