British grandparentsliving overseas are cancelling trips back home to visit their families due to new passport regulations that came into force today.

Lynne and Geoff Crellin had been eagerly anticipating a visit to the UK this summer, hoping to reunite with loved ones and rediscover their home country, which they departed back in the 1970s.

However, the couple from Grimsby, Ontario, is now contemplating abandoning their plans altogether due to the stringent new rules that took effect this morning. From today, dual citizens such as Lynne and Geoff must adhere to new passport requirements when entering the UK as part of the electronic travel authorisation (ETA) scheme, or risk being turned away at the border.

Anyone holding dual British citizenship, children included, must now produce a British passport or another valid passport containing a certificate of entitlement at border control. The certificate carries a one-off cost of £589.

An estimated 1.2 million British citizens now face steep charges simply to enter their own country because they don't hold a valid British passport, despite being British nationals. Up until now, they were able to visit the UK using their alternative passport.

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For the Crellins, the expense and inconvenience is simply not worth the trouble. "This was meant to be a 'trip of a lifetime' - visiting old friends, maybe for the last time, a belated celebration of our recent 80th birthdays and a belated 50th wedding anniversary celebration. We have tried to do a similar trip twice over the last three years, and had to cancel for medical reasons both times," Geoff explained.

"The bottom line is that the new ETA requirement that dual-citizens must enter the UK using a British passport is probably going to cause us to cancel our upcoming three day visit to London. Cancelling our trip is likely to be the most cost-effective and least stressful solution for us, due to the constraints and restrictions put on us by the new ETA rules. The new ETA rules/process, requiring us to buy totally new British Passports, involve a relatively complex process and high cost (over £200), ie, a major new barrier to entry."

Given that the 81-year-olds are unlikely to undertake another journey to the UK, and with their planned summer visit being brief, splashing out on the necessary documents doesn't stack up financially.

"It makes no sense for us to rush to get new 10-year British passports for a three-day stay in London," Geoff explained.

Unless legislation is amended, which appears highly improbable, the Crellins will scrap their trip within the coming weeks, maintaining that it's "a lot of hoops to obtain a new British passport".

Geoff and Lynne are by no means alone in confronting a challenging and potentially costly dilemma. Clive Martin, along with his wife and six other relatives, is arranging a fortnight-long visit to London in June this year.

"When we heard about this ETA debacle, we decided that we could not risk being refused entry to the UK, so we opted to apply for new UK passports. This has cost us approximately $600 (£324) to do," Clive revealed. "Also, because the application process requires that we send our Canadian passports together with our applications, we are constrained from any other travel outside of Canada until the UK government finalises our applications and returns all of the original documents to us.

"I am concerned that, with the introduction of the revised ETA Act, the UK Passport Office may be inundated with applications such as ours, which may impact the time it takes for us to process our applications beyond our planned departure date in June."

A Home Office spokesperson commented: "The UK is moving to a modernised digital immigration system to enhance our border security. From 25th February, international carriers will check all passengers for valid permission or status to travel to the UK - just as they currently do for visa nationals.

"The correct permission for British Citizens is a British passport or a foreign passport endorsed with a certificate of entitlement. At their own discretion, carriers may accept some expired British passports as alternative documentation."