An executive of engineering giant Bombardier, which is axing jobs after losing a lucrative contract to build new train carriages, was dropped at the last minute from joining other business leaders on the Prime Minister's visit to South Africa, it has been revealed.

Colin Walton, chairman of Bombardier's UK transportation business, was contacted by Downing Street on Friday to say he was no longer wanted on the visit.

Bombardier also has an aerospace arm, based in Belfast.

The Rail, Maritime and Transport Union claimed the move was a "disgraceful political punishment" because there had been criticism of the Government's decision to award the £1.4bn contract to build carriages for the Thameslink route to German firm Siemens.

General secretary Bob Crow said: "Not only is this a snub to Colin Walton but it is also a kick in the teeth for the whole Bombardier workforce who are in the frontline of the battle to defend the UK train making industry.

"Only last week the Government were saying that they supported UK manufacturing and Bombardier, and now the head of the last train building company in the UK is removed from the first trade delegation to leave the country since the Siemens stitch up.

"Our members deserve far better than this."

Derby-based Bombardier has said it will cut 1,400 jobs after missing out on the contract.

David Cameron had originally been due to ride on South Africa's Gautrain, which were built at the derby plant.

A huge demonstration is being held in Derby on Saturday to protest at the contract decision and press the Government to change its mind.

UKIP leader Nigel Farage said: "Downing Street has been rather caught out here. Firstly we see from leaked documents that the Government could have defied the EU bidding process and awarded Bombardier the contract.

"Now we find a representative from the company was effectively uninvited from the Prime Minister's current trip to South Africa.

"Actions speak louder than words and this latest development says a lot about this Government's poor attitude in supporting the last remaining train manufacturer in Britain."

Here in Northern Ireland, the company concentrates on the aerospace manufacturing industry where it has emerged as a potential market leader over the last few years.

Bombardier's Belfast plant makes wings for the company's new CSeries aircraft and has managed to secure employment here for 800 jobs following a successful showing at the Paris Airshow.

The company won orders from a number of airlines at the event including Korean Air which placed an order for nearly 40 new aircraft.

Orders for the aircraft also help support the 60-plus local companies which supply Bombardier in Northern Ireland and the 2,000 from across the UK involved in construction of the CSeries wings.