MARITIME union RMT yesterday demanded a public inquiry into the privatisation of the NorthLink ferries contract in 2012 after the discovery that a cheaper public-sector bid had not even been looked at.

Local newspaper the Shetland Times revealed this week that the bid for the Northern Isles ferry service tabled by public-sector operator CalMac — believed to be cheaper than that from Serco, which won the contract — was returned unopened.

RMT general secretary Mick Cash said: “These murky events cast a shadow over the tendering of CalMac’s lifeline ferry services to the Clyde and Hebrides, which is currently under way and which the trade union movement is fighting tooth and nail.”