It's after concerns were raised about the competition posed to Southampton's port.
The Ports Minister Mike Penning has ruled that Liverpool must pay back more of the public subsidy on their cruise terminal.
The government ruling means the Mersey City must pay back £8.8 million as a lump sum or £12.6 million over 15 years.
There were concerns Southampton's privately funded operations would suffer from an unfair playing field as Liverpool had received government cash for basic facilities which they were then upgrading to cater for turnaround cruises.
Southampton Itchen MP John Denham said:
"The Minister’s decision to require Liverpool to pay back more of the public subsidy on their cruise terminal vindicates the campaign that I and many organisations in the city have been running. It shows we were to raise concerns that fair competition was being undermined.
"However, Liverpool is still only being asked to pay back less than half the subsidy they have received. It’s now down to the European Union to ensure that State Aid rules are fairly applied.”