The domestic rate of APD, a tax levied on every ex-UK air seat sold, will be halved from £13 to £6.50 from Saturday (1 April).

Ryanair’s nine new routes include five from Belfast to Cardiff, Edinburgh, East Midlands, Manchester and Stansted. The other four are Bournemouth-Edinburgh, Edinburgh-Newquay, Edinburgh-Stansted and Newquay-Stansted.

The budget carrier, though, has called on the UK government to scrap APD altogether; the tax was introduced in the 1990s as a so-called "green tax" but has never been to put use for specific environmental or sustainability purposes, contributing instead to the general tax pool.

"This 50% reduction ignores international connectivity, which is fundamental for the growth of the UK’s economy and tourism," said Ryanair.

"Ryanair calls again on the UK government to fully abolish APD for all travel immediately, which would not only promote tourism, but also support job growth, and much needed connectivity to the UK – an island-based economy on the edge of Europe."

Jade Kirwan, Ryanair head of communications, confirmed the new routes came in "direct response" to the government’s decision to halve APD, and would almost double Ryanair’s UK domestic schedule compared with summer 2022.

Kirwan added: "While the halving of APD on domestic flights from Apr 2023 has allowed Ryanair to add more domestic routes to our UK schedule for summer 2023.

"If we are to continue to grow and drive a traffic/tourism recovery for the UK, the UK government should immediately scrap APD for all travel and provide incentives for airlines like Ryanair to stimulate growth and recovery for the entire UK market.”