The smiling middle-aged couple from the Italian city of Verona have the tanking pound to thank for making this their cheapest trip yet -- by a wide margin.

"It was a little bit unexpected. We are paying by card and we see that it's not that much compared to euros," Daniela said while waiting for the London rain to pass outside St. Paul's Cathedral.

"This is the cheapest time," said Alberto.

"By far, I think," his wife agreed.

The pound's fall in dollar and euro terms has accelerated as fears of new Prime Minister Boris Johnson taking Britain out of the European Union without an agreement grow.

Chaotic "no-deal Brexit" jitters have seen the world's oldest currency still in circulation lose about three percent of its value against its two main counterparts this week alone.

It has shed almost nine percent since briefly rising when the original Brexit deadline was delayed in March.

The drop since the island kingdom's June 2016 vote in favour of leaving the other 27 EU nations has now reached 16 percent.

"It makes it a little bit cheaper to be here, of course. That's a fact," Dutchman Antol Visser said while his kids wrapped themselves up in rain jackets.

"I don't know what Boris said today, but probably something that dropped the pound."

- Bittersweet -

===============

What Johnson has been saying with growing conviction is that Britain will definitely leave the EU -- with or without a deal with Brussels -- when the new Brexit deadline arrives on October 31.

He is seeking better terms than those struck by Theresa May's former government last year.

EU officials are refusing -- and the big currency traders in London's financial district are getting their first real sense that a messy end to the 46-year relationship may be on the cards.

"Probably it will drop a lot more and at the end of October we will see what happens with no-deal," Visser said.

London lovers from the world over are revelling in the lucky break in what is otherwise a very expensive city -- especially for those trooping around the regular tourist haunts.

A visitor who gave her name only as Ofelia arrived from Mexico City last Thursday and was surprised to see her pesos worth more and more by the day.

"With the level of salaries in Mexico, (foreign travel) is not something everybody can afford," she said in the drizzle.

"But now we could and we are enjoying it a lot."

On the other hand, everyone AFP spoke to was disappointed to see Britain leaving Europe.

"It's always bad news that some member is going out," Visser said.

"We are very sad," Daniela Passarini agreed.

"We think that Great Britain should stay in the EU, not only because of finance or the economy, but because of the idea of a unified Europe."