Police officers carrying Tasers will now patrol outside the Scottish Parliament.

MSPs have been informed of the increased security following last week's Westminster attack.

Police Scotland said the measure was an operational contingency matter and was not based on any intelligence threat in relation to Holyrood.

However, calls for all police officers in Scotland to be equipped with Tasers have been rejected.

The request came from rank and file officers at the Scottish Police Federation (SPF) which was debating whether there should be more armed officers.

The calls were rejected by Deputy Chief Constable Johnny Gwynne who told BBC Scotland the police response to terrorism and organised crime needed to be more nuanced than that and depended, to a large extent, on community co-operation.

'Unarmed service'

He said: "For the avoidance of doubt, we as a command team in Police Scotland pride ourselves in being an unarmed service with the ability to draw on armed capability when we need it.

"We are committed to remaining what looks like an unarmed service, because that's what we believe makes policing work here.

"It is, in essence, a policing model that works right across the UK and that's what we're committed to.

"Where we need armed capability, we can draw on it at speed and in numbers."

Image caption Deputy Chief Constable Johnny Gwynne said when arms capability was needed it could be drawn upon at speed and in numbers

He added: "Bernie [Assistant Chief Constable Bernard Higgins] and his team were able to mobilise at incredible speed last week after the events at Westminster."

Mr Gwynne described the Scottish force as being "match-fit" to deal with events such as those which unfolded in London last week.

Mr Higgins said Tasers should not be looked at "in isolation". He said the force's ability to respond to every level of threat was the central factor.

He said: "It's not just about Tasers, it's about Police Scotland's ability to mitigate every threat level.

"When we look at the threat level, we assess it throughout the country.

"My firm belief is that the number of officers we have trained in the use of Taser and firearms is proportionate to that level of threat."

Security review

The emergency motion at the federation's annual conference asks whether the fight against terrorism risks being undermined by cuts to the policing budget and whether officers have enough personal equipment - including firearms - to be able to protect themselves in the event of a terrorist incident.

Calum Steele, the SPF's general secretary, said more police officers should have the full range of equipment they needed to do their jobs. He said every single officer had the right to be protected.

Image copyright Getty Images Image caption The Scottish Police Federation has been debating whether officers have enough equipment to deal with a terrorist incident

He said the attack at Westminster took less than 90 seconds, and it would take up to 90 seconds to deploy tactical officers in Scotland.

"This has got to be about more than tactical police responses," he said.

"It's got to be about more than machine guns. It's got to be about more than police officers with ballistic helmets, wearing their balaclavas and carrying out a very dangerous role.

"The terrorist attack in Nice, with the truck, was brought to an end by ordinary armed police officers.

"The terrorist attacks at Charlie Hebdo and the Bataclan theatre were brought to an end by tactical firearms officers. There is room for both. You need both."

Proportionate response

Khalid Masood killed three people when he drove a car into pedestrians last Wednesday. The 52-year-old then fatally stabbed PC Keith Palmer before being shot dead.

In the aftermath of the Westminster attack, the number of armed response vehicles on Scotland's streets was increased for 36 hours.

Police Scotland said they had reviewed intelligence resulting in the increased presence around Holyrood.

However, they said the response was proportionate to the level of threat.

In a letter to Holyrood staff ahead of the Police Scotland announcement, Holyrood chief executive Paul Grice said: "Police Scotland will announce this morning that police officers carrying Tasers will patrol the public area outside of the Scottish Parliament building with effect from today.

"Police Scotland has assured us that the move is an operational contingency measure and is not based on any intelligence threat in relation to the parliament or Scotland.

"Following on from the Westminster attack, Police Scotland will undertake a review of its security arrangements at Holyrood. The results of that review will be reported to the SPCB (Scottish Parliamentary Corporate Body) for its consideration."