Calls for a second tug were renewed following the grounding of the Transocean Winner oil rig in Lewis last month.
But the MCA said a consultation and independent review shows there is no need for an additional tug.
The coastguard tug in Stornoway was removed in 2011 under Westminster cost cutting.
The sole designated emergency vessel, MV Herakles -
The transport minister who approved the cuts has been promoted to chancellor.
Philip Hammond will outline the UK government’s spending plans in this week’s Autumn Statement.
Isles MSP, Alasdair Allan, demanded he reinstates the emergency vessel.
Mr Allan said the “cost-
He added: “Cutting this emergency vessel – against all expert advice and the warnings of the SNP – has proven a very unsafe move.
“The grounding of the Transocean Winner rig was an accident waiting to happen after the UK Government made these cuts, and the response time of nearly a full day demonstrates the ongoing risk from having only one emergency vessel.
“It is absolutely vital that the Chancellor uses the opportunity of the Autumn Statement to correct this mistake which has put maritime and environmental safety at risk.
“The Autumn Statement -
A UK Government spokeswoman said: “Earlier this year the UK Government was pleased to announce that we would fund the emergency towing vessel in Scotland for a further five years.
“The tug boat is important for maritime safety and protects the Scottish coast from damaging pollution.
“The Maritime and Coastguard Agency undertook a thorough review of Scotland’s emergency towing needs and concluded that one vessel was sufficient.”
Chancellor urged to use Autumn Statement to reinstate emergency coastguard tug
22 November 2016
Chancellor Philip Hammond faces a call to base a coastguard tug at Stornoway.