B&Q customers who've made use of the retailer's Valspar in-store paint mixing service have complained that the tins are coming open on the journey home and causing thousands of pounds worth of damage to their cars.

As reported by The Guardian, a couple from Fife recently had a five litre can of paint mixed in their local B&Q, only for the tin to pop open in the boot of their new BMW and cause, they claim, £9,000 worth of damage to the car's interior. Said the car's owner Kelly O'Reilly: "You have no idea how much damage five litres of paint can do to a car until it happens to you – it went over everything – our shoes, clothes – everything.

“After three hours of cleaning we were not making any difference – the paint had seeped into the seats. But when we looked at the tin we couldn’t believe how flimsy it was. A 49p milk carton has more protection against spillages than these. They are patently not up to the job of carrying paint.”

Furthermore, the O'Connors from Basildon's Mercedes-Benz was written off by its insurer after a can of the very same paint opened and spilled on the way home. The paint didn't just stain this time, however, it seeped through the car's underbody and shorted the electrics, causing the car to break down. It was then towed to a garage where mechanics declared it too damaged to fix.

According to Guardian Money, there are several more unhappy B&Q customers who have faced similar problems with tins of Valspar paint, which the retailer sells exclusively in the UK.

B&Q has allegedly told customers who complain that it is not responsible for the cans of paint - which carry no warning - once they leave the stores. It has paid out to some victims as "a gesture of goodwill" but has fought other claims through its lawyer Hill Dickinson. Some customers have been forced to claim the damages on their car insurance and face the resulting premiums.

Many of the victims have apparently been in contact with each other to form a group now considering mass legal action to recover all their losses.

B&Q said: "All the products we sell at B&Q are rigorously tested before we put them on sale. In the past year more than three million cans of Valspar store-mixed paint have been bought in our stores, with fewer than one in 100,000 tins leading to a paint spillage complaint.

“On the rare occasion that a customer experiences a problem, we take this seriously, assess the complaint to understand what happened and whether anything could have been done differently. All paint containers used by Valspar meet industry standards and their supplier is accredited by ISO 9001:2015. Despite this, we are carrying out additional testing so that we can remain completely satisfied that the cans are fit for purpose.”