Martin Lewis has delivered an important and poignant episode of the ITV The Martin Lewis Money Show tonight. The financial expert and consumer champion has warned UK households over the importance of a Lasting Power of Attorney.

Mr Lewis explained: "One person in the UK develops dementia every three minutes. Yet relatives can't just walk into a bank and access your money, even if it is to pay for your care. Unless you have a Power of Attorney, loved ones would need to apply through court, which can be long and costly."

There's a compulsory cost of £82 to register a Power of Attorney (in England and Wales – it's £85 in Scotland, £151 in Northern Ireland). If you earn less than £12,000/year though, you can provide evidence to pay a reduced fee of £41. Those on certain benefits are exempt from fees.

Writing into the show, one reader warned: "My mum is deputy (via the Court of Protection) to my dad, who has advanced dementia. It's a very long, drawn out and quite intrusive process. It's also expensive. Mum will have to pay hefty yearly fees too. I just wish we'd managed to get Power of Attorney instead, when Dad was more capable.

"He got ill very fast and we couldn't implement it." Mr Lewis said: "So how does the Power of Attorney work? Well, you nominate a friend or relative to take over your affairs if you lose your faculties, IF. It doesn't mean you're giving up control now."

He said: "Look, I think in many ways, a Power of Attorney is more important than a will, because if you die, you die and the money is going to go on to other people and you won't use it anymore." He went on: "I've had a Power of Attorney since my thirties. I have, thankfully, no foreseeability of losing my faculties. No one takes control of my finances, I'm in control of it, but I have a Power of Attorney to do that. To get when you apply via Gov.uk. It £82, slightly different prices in England and Wales, Scotland and Northern Ireland.

"The best way, if you can, is to get a solicitor to do it, but that will cost £200 to £500, so you have to make that decision. There's partial help from Which? - what that means is, you fill in a template online and then they get a specialist to check it for you rather than having it fully drafted by a solicitor.

"I need to say, Power of Attorneys are not perfect. There are delays at the moment, but my big message it is better to have a Power of Attorney than not. I'm not promising it's a panacea, but it's better than nothing. Now, of course, I talk about financial power of attorneys, because this is what I do.

"But there's also a separate health and welfare one, and exactly how it works varies across the UK, where you give somebody the ability to control your health and welfare decisions, if you lose your faculties too. And I would urge you to look at that one as well. It is important."