Collard, who has raced for rival BMW squad Motorbase these past two seasons, said an opportunity to drive again for WSR – which won 2010’s BTCC with Colin Turkington – was “too good an opportunity to turn down”.

The Hampshireman makes the jump just weeks before the season’s opening round at his home circuit of Thruxton on Easter Sunday 4 April.

Collard previously raced for WSR when it ran MGs in 2005 and 2006. He took two race wins for the squad before his 2008 move to Motorbase. He gave the Kent-based outfit its first two race wins in the BTCC last season and he says it was difficult to leave the team behind.

“This was too good an opportunity to turn down as I could see the WSR BMWs on track last year and at times they were just awesome,” said 41-year-old Collard.

“It was a very difficult decision for me to make a late switch from Motorbase. However, I had to look at what’s best for my career, so to now be driving in a championship-winning team is a real bonus for me.”

WSR Team Principal Dick Bennetts added: “We’ve been in dialogue with Robert for some time and between us we’ve come up with a package of sponsorship, details of which will be announced shortly.

“It will be great to have Rob back with us in a BMW, as he already has two years’ experience in the (BMW) 320si. We are really looking forward to seeing how he performs with our set-ups on the car.”

Collard will be partnered by at least one team-mate – Aylesbury’s Andy Neate who, having miraculously recovered from life-threatening injuries, was announced as a WSR driver last month.

Meanwhile, Bennetts also said WSR is due imminently to begin an intensive pre-season test programme with Collard and Neate and that he is also working to retain his 2009 Champion Turkington in a third BMW.