- Alfie Baron
The Conservatives, Labour and Liberal Democrats all opposed the move but MSPs voted by 68 to 53 in favour of the Railway Policing Bill.
During the debate Transport Minister Humza Yousaf said maintaining high standards of safety and security on Scotland's railways was the government's "primary objective".
He said: "The integration of the BTP in Scotland into Police Scotland will deliver an integrated approach to transport infrastructure policing in Scotland, bringing railway policing alongside the policing of roads, seaports, airports and border policing.
"Integration is about providing a single command structure for policing in Scotland so there is access to wider support facilities and specialist resources. These crucially include Police Scotland's counter-terrorism capabilities."
Mr Yousaf said he remained "absolutely committed" to a triple-lock guarantee on jobs, pay and pensions of railway policing officers and staff in Scotland."
British Transport Police had strongly voiced their opposition to the plans. The BTP said: "Analysis has shown that dealing with incidents can take significantly longer if officers inexperienced in railway policing are the first responders.
"BTP's analysis reveals that offences involving cable theft take on average 33% longer to manage whilst fatal incidents can take almost 50% longer."
It was also pointed out that the railways were policed "in a seamless way which avoids the need for officers to disembark" when travelling across the border between Scotland and England.
British Transport Police also stated: "Specialist train services including nuclear trains, MoD trains and the Royal Train are also currently policed in a continuous manner by BTP operations that consider the implications of the end-to-end route. Introducing new arrangements that necessitate the handing-over of command for any of these services will need to be carefully developed."
BTP chief constable Paul Crowther warned that a merger could prove a "real challenge", saying it could cause a "significant outflow of expertise", but Police Scotland have said a merger would be "complicated but not insurmountable".
Oliver Mundell added: "This is just another ill-thought out power grab, driven not by logic but by an ideological and constitutional obsession with control. It's change for change's sake."
Labour's justice spokeswoman Claire Baker said the government seemed "determined to railroad its bill through parliament", and called on them to halt the plans.
She said: "We have heard numerous concerns from BTP, staff, unions and railway providers that haven't been fully addressed by the SNP. There are clear operational and serious financial questions that remain unanswered by the government.
"We already have in Scotland a transport policing system that works and serves us well, but this Bill risks that. With concerns over the financial memorandum attached to this bill, this could prove to be a costly way to fix a problem that isn't broken."