People who do not disclose information about their pre existing medical conditions and health problems could find themselves with a void travel insurance policy when they need it the most.

That is the warning issued by Sainsbury's Finance, which suggested that 1.3 million people have travelled overseas in the past 12 months without informing their holiday insurance provider of a pre-existing medical condition.

Natasha Virtue, communications manager at the provider, suggested that holidaymakers should not be concerned about common health issues, as most of these will still be covered at fair and competitive premiums.

For people with more severe ailments, it would be advisable for them to seek out specialist travel insurance for people with pre-existing medical conditions.

Ms Virtue said: "Withholding key information such as any medical conditions could result in your cover not being valid, meaning that you're not insured and may well have to finance treatment or even arrange for your own repatriation back to the UK."