Edinburgh trams are to be fitted with defibrillators as part of a campaign to save the lives of heart attack victims.

Quick use of the devices is said to increase survival rates by up to 75%, and charity St John Scotland is installing the defibrillators which come with a recorded message to explain how to use them.

Each one costs around £1,500 with funding for their installation coming from public donations and businesses including the Royal Bank of Scotland, Virgin Money, Montagu Evans, Charlie Miller, GLM, Phillips and Laerdal, and Newtyne Consultancy and Training.

Edinburgh's Lord Provost Donald Wilson launched the project and said: "Nobody in Edinburgh should need to think twice before using a defibrillator in an emergency, which is why I am delighted St John and the City will be offering advice and training to tram staff.

"Not only can the machines help passengers in need, they can be taken off the carriage and used at tram stations."

It comes after the Scottish Liberal Democrats called for all primary schools across Scotland to have life-saving defibrillators installed.

Speedy use of the heart-starting equipment can help boost survival rates of heart attack victims, but only one of the 26 local authorities which responded to a Freedom of Information request have the machines in all of their primary schools.

Each year, only around 5% of the 3,500 people in Scotland who undergo attempted resuscitation outside hospital for a heart attack survive to hospital discharge.

Lynn Cleal, fundraiser chair of St John Scotland, said: "We are delighted to bring together the donor businesses with Edinburgh Trams to install these life-saving defibrillators now giving a lifeline right across the City.

"The St John and the City project is committed to making defibrillators more accessible to members of the public and as they will now be on every tram, we hope that they will be able to save more lives in Edinburgh."