Ryanair is scrapping 20 of its 23 Glasgow Airport routes, putting up to 300 jobs at risk.

The budget airline announced plans to close its west coast base at a press conference on Tuesday.

Ryanair will only fly to Dublin, Wroclaw and Krakow from Glasgow as of November, but intends to add 11 new routes from Edinburgh Airport.

Chief commercial officer David O'Brien blamed Brexit and air passenger duty (APD), calling it a "threat to Scottish tourism and jobs".

He added: "Ryanair regrets these cuts in the weaker Glasgow market where efforts to stimulate low fare demand are severely hampered by the continuing burden of APD.

"As a result we will transfer our Glasgow International-based aircraft to Edinburgh in November where we will offer 11 new low fare routes - 45 in total including London Stansted - and deliver over 3.5 million passengers per annum at Edinburgh Airport."

The Scottish Government wants to replace APD with air departure tax (ADT), which could make flights cheaper for passengers.

One Ryanair aircraft and five routes - Derry, Lisbon, Sofia, Riga and Berlin - will switch from Glasgow to Edinburgh Airport in November.

Glasgow Airport said about 100 jobs would be directly affected by Ryanair's decision, while the airline estimated up to 300 could be lost more widely.

A spokesman for Glasgow Airport said: "We are bitterly disappointed at this decision by Ryanair, which is not only damaging for Glasgow and wider Scottish connectivity, it will impact approximately 100 jobs locally.

"This is a result of the airline's review of its single aircraft bases, however we have been left in no doubt it is also a consequence of the Scottish Government's inability to introduce its proposed 50% cut in ADT.

"Despite clear and repeated warnings from both airports and airlines about the potential impact of this policy not being implemented, we are now faced with a stark scenario that includes the loss of 20 services and a significant number of jobs.

"This is the second example in as many months of an airline cutting capacity in Scotland because of the lack of movement on ADT.

"The reality is this capacity will be reallocated elsewhere in Europe to countries with more favourable aviation taxation policies to Scotland's detriment. We cannot sit back and risk Scotland's connectivity being further eroded. It is imperative there is immediate action on ADT."

The Scottish Government said it remains committed to halving ADT by the end of the parliament but pointed to problems securing an exemption for passengers travelling from Highland and Island airports.

Finance secretary Derek Mackay said: "This news from Ryanair is clearly very disappointing for Glasgow Airport and the staff who will be affected.

"The continued uncertainty around Brexit is having a negative impact on route development in Scotland.

"We will continue to work to work in partnership with Ryanair and other airlines, and to support all Scottish airports, to do everything possible to grow the number of international routes to and from Scotland.

"The Scottish Government continues to be committed to reducing ADT by 50% by the end of this Parliament and we want to get on and deliver this.

"But this has been deferred until the issues raised in relation to the Highlands and Islands exemption have been resolved to ensure that the devolved powers are not compromised."

Ryanair had already cancelled all flights between Scotland and London until March as a result of pilot shortages.

It scrapped 2100 flights across the UK after "messing up" pilot holidays last year, a mistake which cost the airline nearly £44m in refunds and compensation.

Ryanair opened its base at Glasgow Airport in 2014 and also flies out of Prestwick.