(14 Mar 2021, 6:09 pm)streetdeckfan wrote It means that cost is going to be the primary measure for awarding the contract.

Put simply,
GNE could offer to run the services using brand new electric buses, with contactless payments, next stop annoucements, free WiFi, USB, air conditioning, leather seats, tables, and free refreshments for £10 (completely made up number)
GCT could offer to run the services using older vehicles where the nearest you'll get to a next stop announcement is getting "last stop" shouted at you by the driver, with absolutely no creature comforts for £9 (again, completely made up)

Because they don't take any of the 'quality' into consideration, GCT would likely win the contract because they were cheaper.

In their own words: 

"5.23 The criteria on which Nexus shall base the award of public contracts shall be either:
 Most Economically Advantageous Tender - when the award is made to the tender most economically advantageous from the point of view of Nexus. This involves various criteria linked to the subject matter of the public contract in question (e.g. quality, price, technical merit, aesthetic and functional characteristics, environmental characteristics, running costs, cost effectiveness, after sales service and technical assistance, delivery date and delivery period or period of completion); or
 Lowest Cost - Lowest cost should be calculated on a whole life basis."