Jaguar Land Rover is set to deliver a huge boost to the automotive sector by revealing it is doubling the size of its new engine plant in the West Midlands.

The rapidly expanding car giant is going to create 700 extra jobs at its new i54 plant in Wolverhampton by investing £500 million to double capacity – before it has even opened.

Insiders say the move came after global demand has continued to rise since the plans were first announced.

Initially the company said it would invest more than £350 million in the factory, creating more than 700 jobs, but the new plans will now see up to 1,500 jobs created.

An insider told the Birmingham Post: "Sales are going incredibly well. Market share is up and they believe they need to act quickly, even though the first phase is not constructed yet."

The factory on the i54 site, between Wolverhampton and Telford, will build engines for Jaguars and Land Rovers and is expected to be ready to start engine production in 2014.

The Gaydon-based luxury car maker is planning to more than double the number of its vehicles made annually to 600,000 by 2020.

A spokesman for Jaguar Land Rover declined to confirm the move.