The deal has been done in the form of shares with the investment used to improve facilities for both passengers and airlines.

The money will also be used to ensure the airport, in tandem with the city, can become a key gateway to the government’s Northern Powerhouse project.

The council is now one of two joint venture companies to invest in the airport in the hope it will make a commercial return.

Mayor of Liverpool Joe Anderson said: “John Lennon airport delivers a huge economic boost for the city region, employing thousands of people directly and indirectly.

“It is the gateway to the city from many destinations and it is absolutely vital that it continues to grow, create more jobs, boost economic growth and develop tourism.

“This opportunity to play a more active part in its future expansion and success makes it a sound investment for the city council.

“This is part of our Invest to Earn strategy where we are able to make investments that deliver a return which we can then plough back into supporting council services.

“This funding can only be used for investments and we are not taking money away from frontline services for it.”

Robert Hough, chairman of Liverpool John Lennon airport, added: “We are delighted by the city council’s decision to invest.

“This investment complements the council’s existing role in supporting the local and regional economy and allows the city to share in the financial success of the airport.

“They will bring strong support both financially and strategically, with interests aligned to those of Peel and the wider city region.”

Passenger numbers at the airport in 2015 were 8% up on 2014 - the highest since 2012 and are already over 20% for the year to date in 2016.