THE number of addresses which have been flagged up as dangerous for Scottish ambulance crews has more than doubled in less than a year.

The latest Scottish Ambulance Service figures showed there were 1213 addresses in which staff were able to request police back-up before they attended an incident.

This compares with figures released in May last year, which revealed the total number of addresses was 593.

Overall, the statistics reveal that Hamilton is the most difficult town for 999 crews to work in, with 13 addresses flagged up because of previous violence towards staff.

It emerged last year employees at the South Lanarkshire town's ambulance station were assaulted 29 times in the three years up to 2012.

The postcode area which ­encompasses Paisley and Glasgow Airport is second on the list, with 12 addresses deemed to be too risky for crews to visit unescorted.

In third is the postcode for the South Ayrshire seaside town of Troon, where 11 addresses have been highlighted.

Two postcodes covering ­neighbouring communities in North Ayrshire - Saltcoats and Ardrossan - had 10 addresses on the list.

Many of the problems were caused by people assaulting or abusing crews after drinking too much alcohol.

However, an ambulance service source said the figures can rise and fall as the information about certain addresses was reviewed regularly. The insider added: "Addresses are added or taken off as appropriate."

The service called for its staff to be given more respect by certain sections of the public.

A spokesman said: "If a 999 call comes in from a flagged address, dispatchers can identify that staff may be at risk and request additional police support. If any crews feel their safety may be compromised they are instructed to hold nearby the scene and await support from the police, or additional ambulance crews."

"Every year, ambulance crews report incidents of physical assault, ranging from pushing and punching to spitting and attack with a variety of weapons.

"They deserve more respect for their dedication to patient care, often provided in the most challenging of situations. In most of these incidents alcohol is a key factor in the aggressive behaviour of patients."

David Forbes of Unison, which represents many ambulance staff members, said: "We find it outrageous that any member of any public service should be under the threat of violence as they attempt to carry out their work."

Scottish Conservative health spokesman Jackson Carlaw MSP said: "It's a disgraceful reflection on our society that so many ambulances should be effectively banned from attending those in need.

"These are self-exclusions by individuals who show no regard for the very people who are trying to assist them.

"Paramedics do a valued and brave job, and simply should not have to put up with this type of scenario."

Other areas flagged up as ­troublesome include an area of Inverness which has nine properties where crews cannot travel without back-up.

Five postcodes on Islay contain 14 "red-flagged" addresses.