A SERIES of potentially lethal flaws in Holyrood security have been uncovered in the wake of the terror attack in Westminster which left five people dead including the killer.

Concerns focus on the car park beneath the Scottish Parliament which could be vulnerable to a terrorist car bomb, and the personal security of the First Minister. There are also concerns about the use of parliamentary passes, and the lack of pin codes in use in Holyrood.

Pass-holders entering the car park do not have their vehicle or car boot searched, nor are mirrors used to search beneath the vehicle. It is also understood the First Minister is not routinely accompanied by armed protection officers.

There have been previous high-profile attacks where terrorists used car parks to attack buildings, including a 1993 attack on the World Trade Center in New York, where an al-Qaeda car bomb in the car park beneath the building killed six and injured more than 1,000.

In 1979, Tory Northern Ireland spokesman Airey Neave was killed when a car bomb fitted under his car exploded as he drove out of the Palace of Westminster car park.

A source close to the First Minister when asked if she had a regular armed detail attached to her since the attack in Westminster said "not as far as I know". Officially, a spokeswoman for the First Minister would only say: "We don't comment on security matters."

During the Westminster attack, it was a plainclothes firearms officer, part of Defence Secretary Sir Michael Fallon’s detail, who shot dead attacker Khalid Masood after he had fatally stabbed PC Keith Palmer and before he could get further into the parliament.

Present and past Prime Ministers, and UK ministers thought to be at risk, have round-the-clock armed protection.

Professor Stephen Vertigans, an expert in political violence at the Robert Gordon University in Aberdeen, said increased security for high profile politicians was likely to become more commonplace.

He said: "I'm sure there will be greater security and the safeguarding of key figures and leading politicians. There will probably be a greater police presence at high-profile locations.”

Heavily-armed uniformed police have patrolled the Houses of Parliament for more than a decade - however, none of the MSPs contacted by the Sunday Herald, while calling for a greater police presence, wanted armed police at the Scottish parliament.

And while security at the entrance to Holyrood has been strengthened there are no routine checks of cars and boots or the use of extendable mirrors to look under vehicles for bombs, as happens at the UK parliament.

One former MSP, who wanted to remain anonymous, said that while he is “satisfied” with security, access to the car park below the Parliament was an area that could be reviewed.

He acknowledged that security had improved, but pointed out that deliveries and other vehicles enter Holyrood and suggested “boot checks” were an option.

The Sunday Herald asked the Scottish Parliament a series of questions relating to security of the car park, including whether mirror checks underneath cars were necessary and if boot checks could be carried out.

A spokesman said: “The service yard and car park area were both reviewed following the Ottawa attack [on the Canadian Parliament] and improvements put in place in early 2016. The improvements were made on advice from Police Scotland and other security partners to meet current and emerging threats.”

Counter-terrorism expert Charles Bird, who worked for the UK Government, including the Ministry of Defence, for a number of years, and is now based at the Centre for the Study of Terrorism and Political Violence at St Andrews University, said issues such as the security of the car park would be a concern.

He said: “It would be tempting to think the main target is Westminster, but one of the things we have seen with terrorist groups and individuals is that if you harden the high-profile targets, you get a switch to softer targets and ones that are easier to get to.”

Another MSP defended the access arrangements to the car park, but flagged up concerns about the pass-operated system. If an individual stole a pass, the MSP said, the same person could access almost all areas of the Parliament.

MSPs and other workers based at the site are vetted before being given security passes to access the building or car park – but Westminster has an additional layer of protection with pin codes also required at all entrances. It is not possible to get onto the UK parliamentary estate there without entering the pin.

A Holyrood source said: “All pass holders are advised not to wear their pass when outside the building. This advice was reiterated to all building users in the wake of the attacks on Westminster. Furthermore, pass usage is regularly monitored and all passes are immediately disabled if reported lost or stolen or the pass holder leaves the organisation.”

Asked how many passes had been stolen or lost, a Holyrood spokesman said: “The information you requested is not held and therefore we cannot provide it to you, the reason for this is because when a pass is reported as lost to the Security Office, it is immediately disabled and a replacement pass is issued to the pass-holder, consequently there is no requirement to record the number of passes reported as being lost.”

John Cuddihy, former detective chief superintendent and head of counter terrorism with Police Scotland, said all parts of the UK should continually review security provisions.

He said the extent of security measures was driven by the threat level, which is currently set at severe – meaning an attack is likely but not imminent.

But he added: “Whilst this threat level covers the whole of the UK, each area within the UK will respond in line with the intelligence/information available.”

Police Scotland assistant chief constable Bernard Higgins told the Sunday Herald he had met Sturgeon to discuss her safety as part of the force's heightened security measures since the terrorist incident in London.

Higgins said he could not disclose the nature of the briefing for security reasons, but said he had given the First Minister "very general" advice on her protection.

Higgins also said Police Scotland would maintain the number of armed officers on the streets well into next week, including keeping armed police response vehicles near the Scottish Parliament.

He added that "at some point normal operations level will return", but refused to state when this would be for security reasons.

Professor Dr Phillips O'Brien from the School of International Relations at St Andrews University said there should not be a dramatic security clampdown in the long term.

He said: "We always knew there was a chance this could happen and it shouldn't lead to any change in security in the long term. On the whole there are remarkably few attacks in the UK, so there should not be anything drastic. You shouldn't bring in big changes because of one event."

After last week’s attack MSPs also received a security briefing. Becky Thomson, the Scottish Parliament head of security, confirmed that the UK threat level was “severe” but confirmed there was “no intelligence” to suggest a specific threat to “Scotland, Edinburgh or Holyrood”.

However, the events at Westminster have inevitably kick-started a debate about whether security at Holyrood is fit for purpose.

In October, it was revealed that more than 6,800 potential weapons had been seized from visitors to Holyrood since 2014.

Most of the dangerous items seized by Holyrood security officers were knives, with 5,832 blades found, followed by 556 screwdrivers/corkscrews and 440 scissors.

However, a source warned against the idea of a perfect security system: “If somebody wants to get in, there is no way of guaranteeing that won’t happen.”