Police officers on Scotland’s railways are to be given Tasers to increase security on the network.
British Transport Police (BTP) said a “proportionate” number of specially trained officers would be equipped with the device.
The force cited an incident at Leytonstone station in east London in December where police used a Taser on a man who slashed a stranger, stopping him from harming further passengers.
However, the decision puts the BTP at odds with Police Scotland, which allows only firearms officers to carry Tasers.
The Scottish Government intends to integrate BTP into Police Scotland, despite concerns being raised that it will undermine policing on the railways.
Alun Thomas, temporary assistant chief constable of the BTP, said: “This decision is not based on specific intelligence of any criminal behaviour or imminent threat, but will allow us the option to deploy Taser devices where, in the course of their duty, an officer needs to protect the public or themselves by using force.
“The current threat to the UK from international terrorism remains ‘severe’, meaning an attack is highly likely.
“Recent terrorist attacks across the world are a stark reminder that the threat from terrorism is a genuine risk and it is important that we keep our security measures and operational tactics under constant review.”
Last year, the Scottish Police Federation, which represents rank and file officers in Police Scotland, called for Tasers to be kept in every patrol car.
Unlike in England and Wales where officers are routinely armed with Tasers, fewer than 300 armed police officers in Scotland carry the stun gun.
While Tasers were fired 1,730 times by police in England and Wales in 2015, the figure for Scotland was just two.
Lib Dem justice spokesman Liam McArthur said: “The decision to equip officers with Tasers is not one that should be taken lightly. As with the deployment of armed police officers, we must have robust reassurances that their use will be proportionate to the threat level.
“Security and safety are vitally important, but so too are our rights as citizens. The BTP may be justified in taking this decision, but the public will need to have confidence that the way in which it is implemented and its effects are being very closely monitored over the months ahead. This is something the parliament’s justice committee will no doubt wish to do.”