The number of blacklisted homes where ambulance staff request police protection before entering has risen by one-third, new figures show.

A snapshot of blacklisted homes last month shows 593 addresses have been "red flagged" because of attacks or threats on paramedics, an increase of 156 from last year. Ambulance staff cannot enter blacklisted properties unless police are present, even in the most serious of emergencies.

NHS Lothian had the most red-flagged addresses with 162, followed by Greater Glasgow and Clyde with 147, and Fife with 68.

Lothian also has the most disproportionate number of blacklisted homes for its size, with one red-flagged property per 5000 people in the city, compared with one per 8000 in Glasgow.

Fife and Forth Valley also have a high proportion of blacklisted properties.

Conservative health spokesman Jackson Carlaw, who obtained the figures, said: "This is a disgraceful situation, and those who have caused this only have themselves to blame if they lose out on medical treatment in the future.

"The safety of our emergency workers has to be absolutely paramount, and it is right the ambulance service takes these precautions.

"You would expect there to be the odd address which would be blacklisted, but for several hundred to fall under this description is quite staggering.

"It shows, despite SNP claims, we still have a real problem with crime and disorder in Scotland, and it needs to be clamped down on."

A spokesman for the Scottish Ambulance Service said: "The safety of ambulance staff is paramount, which is why the service takes appropriate measures to protect them. All crews are given training in management of aggression and how to undertake a full risk assessment on arrival at scene to establish if there is any potential danger.

"Addresses where there have been incidents of violence or threatening behaviour towards staff, are flagged in control rooms. This means if a 999 call comes in from a flagged address, dispatch staff can request additional police support."

A Scottish Government spokeswoman said: "Violence against NHS staff is unacceptable and will not go unpunished. However, crime is at a 37-year low in Scotland and this represents a very small proportion of around 2.5 million residences across the country."