Queen Elizabeth's favourite train will no longer be scrapped.

Queen Elizabeth

Queen Elizabeth

The 90-year-old monarch was left devastated when she learnt three years ago that the Royal Train was no longer cost-effective and would only have between five and 10 years left before it would need to be destroyed, but plans to demolish it have now been axed after tests carried out came back positive.

A source told The Sunday Telegraph newspaper: "There is no end in sight to its use, and no fixed agreed horizon in terms of when it will be inoperable or decommissioned."

The future of the train was thrown into jeopardy after Sir Alan Reid told MPs a few years ago that it was no longer fit for purpose due to its age.

However, a palace insider said: "Sir Alan Reid reported to Parliament a few years ago that the train may have to be decommissioned shortly. But since then tests have revealed it has more life in it than previously thought...

"For the Queen and members of the Royal Family it is a sensible and cost effective way of travelling, enabling them to stay the night close to the location of an engagement the following day - but without causing the disruption or security costs that, say, a hotel in a city centre would entail."

The tests were carried out after the queen made it clear that the Royal Train was her favourite mode of transport and she still relies heavily on it running for her.

Penny Junor, Prince Charles and Prince Harry's biographer, said: "The train is very dear to them. It's fine for them to travel on public transport, but on the Royal Train they can sleep and, as the Royal Yacht was, its somewhere completely private, with everything they need on board. Everybody knows what it means to them. Yes, there's a cost attached to it, but there's a cost attached to having a Monarchy and it is what we want as a country."