The Liberal Democrats have been criticised after it emerged the party refused to meet the £800,000 policing cost of its UK party conference in Glasgow last year.

Police Scotland has now informed Nick Clegg's party that it will only provide a basic service for this year's gathering in the same city, which started yesterday.

The Home Office pays around 85% of policing costs for party political conferences south of the Border, and local forces are responsible for the remaining amount. According to official statistics, around £50 million has been spent on policing conferences over the last five years.

However, the funding deal does not apply in Scotland, as policing is a devolved matter and comes under the control of Justice Secretary Kenny MacAskill. The LibDems staged their UK conference in Glasgow last autumn, but no subsidy was available for the five-day event.

The Sunday Herald has learned that Police Scotland and the LibDems clashed over the unmet costs. The force believed the party was liable for the £800,000 cost, but the LibDems took a different view.

As a result, the party will have to rely on private security to bolster any low-level police presence at the Scottish Exhibition & Conference Centre this week.

The issue is sensitive as the Scottish LibDems have been at the forefront of the campaign against police budget cuts. The party opposed the creation of the single force and its MSPs have complained about the loss of thousands of jobs.

Party sources said previous policing bills were absorbed by local councils, but with the advent of Police Scotland in 2013 the Scottish Government inherited the bill and SNP ministers had refused to pay up "because they hate the LibDems and Tories".

Conferences bring their host city extra revenues in hotel bookings, but the events are also money-­spinners for political parties. According to the latest LibDem accounts, the party made a £511,385 profit on its conferences last year, up from £405,433 in 2012.

MacAskill last year called for the Home Office to pick up the tab for the LibDem conference, but no agreement was reached.

Police Scotland assistant chief constable Bernie Higgins said: "Police Scotland met representatives of the Liberal Democrats and we said we would provide a level of service, but the majority of security would be provided by the private security industry."

SNP MSP Sandra White said: "It is astonishing to learn that the party hasn't picked up the tab for policing last year's event. The LibDems should pay up and support our policemen and women."

A Scottish LibDem spokeswoman said: "In line with Acpos guidelines, the Scottish Government should absorb the majority of policing costs which come with any high-profile event. Last year, the Scottish Government refused to do this.

"We have increased our own security provision this year and are working with Police Scotland to keep associated costs down."

A Home Office spokesperson said: "It is a devolved matter for the Scottish Government and Police Scotland."