Scottish Government plans to merge railway policing have suffered another setback after it emerged that the senior civil servant associated with the policy is leaving his post.

Don McGillivray, deputy director of the Police Division, has accepted another job on the environment side of the Government which he will start shortly.

However, critics of the plan to integrate the British Transport Police with Police Scotland believe the McGillivay move shows that the policy is in trouble.

Nigel Goodband, chair of the BTP Federation, which represents police officers, said:

“It is concerning that Mr McGillivray has moved on at such a critical stage in the integration process. Not only was he joint Chair of the Joint Programme Board but an architect of police devolution, having been involved for several years.

“The realisation that a successful and safe integration cannot be delivered by April 2019, the significant challenges that still need to be overcome, and now the departure of such a senior figure in Mr Gillivray, all point to the need for an independent body to oversee the integration process."

Powers over railway policing were devolved to Holyrood as a result of the cross-party Smith Commission recommendations.

As a consequence, the SNP Government brought forward an enabling bill to merge BTP with Police Scotland, legislation that was passed last year.

However, opposition parties and industry stakeholders opposed the merger on various grounds, including cost and whether change was necessary.

The amalgamation was supposed to be in operation by spring 2019, but the breadth of of concerns expressed about the policy led to the merger being delayed.

McGillivray was a key civil servant who worked on the proposals behind the scenes for Justice Secretary Michael Matheson.

He gave evidence to MSPs at Holyrood on the Railway Policing (Scotland) Bill and has been a Scottish Government representative on the board overseeing the implementation of the Act.

In December, it emerged that McGillivray had tried to persuade a watchdog to water down criticisms of the BTP merger.

Emails revealed that he tried to get Her Majesty’s Inspectorate of Constabulary in Scotland (HMICS) to change parts of a report that exposed key aspects of the policy.

Correspondence released by HMICS showed a sustained attempt by McGillivray to challenge the “business case, benefits and disbenefits” section of the document.

It is understood McGillivray recently applied for a new post in Government and was successful.

Dr Kath Murray, an academic who has criticised the Government on BTP said:

"The size of this task was seriously underestimated by officials. With escalating costs and heavy reliance on consultants, it’s clear that the decision not to undertake detailed cost-benefit analysis was badly misjudged. I’d suggest that integration should now be suspended and the options reviewed.”

Labour MSP Daniel Johnson said: “This politically motivated merger, which officers in the British Transport Police do not want, is a complete shambles and now it looks as though the civil servants are distancing themselves from it.

“The SNP’s centralising plan for the BTP should now just be called off entirely and the government should listen instead to alternatives proposed by the BTP Federation.”

Tory MSP Liam Kerr MSP said: “Given this latest predicament it’s time the SNP finally realised that this project is falling apart and needs to be ditched altogether.”

A Scottish Government spokesman said: “We are working with the UK government to ensure the legislation introduced by Ministers and passed by the Scottish Parliament last year is implemented as effectively as possible, providing an enhanced service to both the rail industry and travelling public.

“Clearly Ministers are responsible for determining policy. The development and implementation of railway policing integration has involved and will continue to involve a considerable number of policy officials, also working with several agency partners.