Vauxhall's Ellesmere Port plant will continue to produce the new Astra, and its successor, until at least 2022 after the workers' union Unite struck a deal with Magna - the company planning to take over GM Europe.

In return for Vauxhall workers accepting a two-year wage freeze, voluntary redundancies and extensive cost-cutting measures, Magna and Unite have agreed that production of the next-generation Astra, set for 2016, will remain at Ellesemere Port - subject to the plant maintaining its competitive position. With the Astra on a seven-year replacement cycle, that takes the plant up to the end of 2022.

Vauxhall's Luton plant was also guaranteed production until 2013, when its current contract to build vans with Renault expires.

Business secretary Lord Mandelson has welcomed the news, but has still to agree on how much state aid Britain will offer to Magna.

However, question marks still linger over the Magna/GM Europe deal, with European commissioners investigating Germany's role in smoothing the deal by promising multi-billion euro loans.