Sales of cars are set to increase over the next few months, according to a survey.

As many as 18% of adults intend to make a vehicle purchase in the period to August, the poll by Sainsbury's Bank found.

This represents 8.33 million people and is well above the 5.56 million who said they planned a purchase between September 2011 and this February.

The amount expected to be spent on changing vehicles is also much higher - up from £40.2 billion in the period September 2011 to February 2012 to just under £90 billion in the period March-August 2012.

In the period between March and August this year, the East Midlands has the highest proportion (26%) of people who plan a car purchase, with the north-west of England being the area with the fewest potential buyers (14%).

As many as 26% of 18 to 34-year-olds intend to buy a car over the next few months, compared with 18% of those aged 35-54 and only 10% of those aged 55 or more.

Of the 8.33 million potential buyers, around 1.6 million are looking for a car that better suits their family's needs, while more than three million people are looking to change their car to reduce the costs - either cutting down their engine size or switching from a petrol car to a diesel one to reduce fuel and road tax costs.

Steven Baillie, head of loans at Sainsbury's Bank, said: "Our car-buying index provides a good indicator of consumer confidence, which seems to have increased since last September. This has been helped potentially by the number of offers and deals available."