Martin Lewis has issued passport alerts to anybody planning to travel abroad this summer. The founder of Money Saving Expert told viewers of his Martin Lewis Money Show on ITV that countries are getting stricter on who they let in so Brits need to be "more diligent" with their own checks.

He shared three "crucial" alerts, including two passport checks to be done of the day you enter a country. Mr Lewis said: "Very importantly, this is about the day you will enter the country."

The expert said people need to check if there are less than six months left on their passport, or fewer than three for those travelling to the European Union.

He added: "If so, that's a big problem. But even if you had seven months left on your passport - if your passport is over 10 years old, many countries won't let you in."

Mr Lewis explained that this might be the case for people who had time left on an old passport which was transferred when they renewed their passport.

He warned people need to do both those checks and if the answer to either is "yes", then the "safest" thing to do is to renew your passport before travelling.

In the UK, it usually takes about three weeks to get a passport, but may take longer if the Passport Office needs more information about you.

In such cases, you should be told within three weeks. Anyone applying from outside the UK should expect a different length of time.

It is cheaper to apply online, although you can apply on paper from a post office. Doing so costs an extra £16.

Mr Lewis explained that even if his passport had seven, eight or even nine months left on it and the rule was six months, he would still "play safe" and renew it anyway.

He added: "It's very similar if you're travelling to the USA or passing through the USA. You need to sort your ESTA now."

The Electronic System for Travel Authorisation (ESTA) is a system used by the US to screen travellers who want to enter the country under its Visa Waiver Programme (VWP).

It allows people from participating countries to travel to the United States for business, tourism or transit for up to 90 days without a visa. British citizens are eligible to travel under the VWP.

Mr Lewis said: "There is heightened border security in the States. If you don't have [an ESTA]... without one people are being denied entry. You need to be careful."