Ryanair is raising the pressure on Lufthansa in the German flag carrier’s back yard.

The Irish low-fares carrier, which has called for action to prevent Lufthansa taking over assets from troubled rival Air Berlin, is adding 34 new routes from the German airline’s hub at Frankfurt Main airport to give a total of 38 for next summer.

An additional destination is also being added to bring Ryanair’s network from Frankfurt Hahn airport up to 43 routes.

The expansion from Frankfurt Main will see three additional Ryanair aircraft being deployed to give a 10-strong fleet based at the airport for summer 2018.

The combined growth at a cost of $1 billion will see Ryanair carry more than 4.7 million additional passengers next year from the two German airports.

The bulk of new routes from Frankfurt Main are to sun destinations in the Mediterranean, Portugal and the Canary Islands but also include a daily service to Manchester, two flights a day to Stansted and six a week to Manchester.

Ryanair chief commercial officer, David O’Brien, said: “We are pleased to announce an additional three based aircraft at Frankfurt Main to bring it to a total of 10 and an investment of $1billion.

“We have also launched our Frankfurt summer 2018 schedule with a total of 81 – 35 new – routes to/from both Frankfurt Main and Frankfurt Hahn, which will deliver over 4.7 million customers through the two airports.

“German customers and visitors are booking our winter 2017 seats in record numbers as fares continue to fall.”