Research commissioned by Moneysupermarket.com found that a hardcore of 2.5 million GB motorists would commit fraud rather than risk jeopardising a car insurance claim.

The survey by YouGov, asked UK motorists what they would do if they forgot to lock their car and it was stolen. Less than one in five (18%) said they would disclose the full facts without being pressed and 41% would own up to their mistake if asked, while a further 26% would withhold the truth until they felt the pressure was too much.

Richard Mason, managing director of insurance at Moneysupermarket.com, said: ?It?s extremely worrying that one in three drivers would actively attempt a cover-up if their carelessness led to a claim.

?People may not see the omission of certain facts as fraud, but if these facts helped lead to the claim then that?s exactly what it is. We would urge all drivers to tell the full truth; insurance fraud is a criminal offence and the overall consequences could be far more costly than the sums they are trying to salvage by being economical with the truth.

?A conviction for fraud will leave a lasting impression on the individual?s life and the insurance industry may well refuse to cover them in future, meaning they can no longer drive at all.?

The results also showed that men are more likely to withhold the truth with 11% professing total innocence compared to 6% of women drivers. Welsh drivers are most honest, with 25% saying they would tell all without prompting, compared with 10% of those from the North East. Scottish motorists were the least likely to refuse to give full details under pressure, with only 5% choosing non-disclosure.

Richard Mason added: ?Insurance companies are often seen as the bad guys, but there are two sides and drivers need to own up to their mistakes. In such circumstances, insurers will assess the full details of the claim and are generally pretty reasonable when it comes to paying out.?

The price comparison website Moneysupermarket.com, today reveals the top ten most competitive motor insurers throughout 2006, with swiftcover car insurance emerging as the most consistently low-cost brand.

From an analysis of over three million premiums quoted through Moneysupermarket.com?s car insurance comparison service in 2006, swiftcover.com returned the cheapest average premium for all drivers at £276*.

Other names that made the top five were Post Office, Zurich, More Than and Liverpool Victoria. Big brands such as Barclays car insurance and the RAC also made the top ten, as well as supermarket bank, Sainsbury?s.

Richard Mason, managing director of insurance at price comparison website, Moneysupermarket.com, said: ?It is not surprising to see the younger, nimbler online insurers providing consistently competitive premiums given their lower overheads when compared with the traditional insurers. It is encouraging however, that some of the big names such as Barclays and RAC are still committed to offering consistent good value, but they are not quite able to pip swiftcover.com to the top spot.?

The research also reveals that Debenhams, not a well-known player in the motor insurance market, offers the most expensive average quote for all drivers. The average premium quoted throughout 2006 was nearly £1,500 ? over five times more expensive than swiftcover.com on average. And despite building up a name in the motor insurance industry for being the ?fourth emergency service?, AA Insurance languishes at the bottom of the tables.

Richard Mason continued: ?It's disappointing to see a big motor insurance brand, such as AA Insurance, at the bottom of the table. With well-known brands, such as RBS saying its customers will see double digit percentage hikes in their premiums this year, millions of motorists need to be careful when it comes to renewing their policies and they could receive hefty renewal quotes.

?With fair-weather insurers changing their pricing strategies overnight to meet their business targets, consistency is a useful gauge of which brands to consider. But there really is no substitute for spending just a few minutes comparing the market, when you want to know you are getting the best value deal for your circumstances.

?Insurers automatically include discounts on the first year of a policy to entice motorists in, hoping they will stay when this ?honeymoon? period comes to an end and premiums take a turn for the worse. However, there is nothing to stop drivers changing their insurer every year and therefore always taking advantage of these introductory bonuses.?