London skyline
For the first time in 15 years, the substantial decline now makes London less expensive than New York. iStock

Singapore and Hong Kong retained their respective positions as the two most expensive cities in the world, while London slipped 18 places to 24th this year in the global cost of living ranking. This is London's lowest spot in two decades.

According to a report by the Economist Intelligence Unit (EIU), Brexit uncertainties and a depreciation of the pound have been listed as the reasons for London's new position.

For the first time in 15 years, the substantial decline now makes London less expensive than New York. The City is now on par with Dublin and cheaper than Paris by 17%.

Manchester was calculated as the city which tumbled the greatest in the survey rankings, falling by 25 places to the 51st spot.

The steep decline of the two British cities merits a serious examination of Prime Minister Theresa May's post-Brexit strategy, as she might invoke Article 50 by March 29th. "Intense competition among British retailers accompanied by low oil and commodity prices has kept significant rises in check over the last few years" mentioned Jon Copestake, the EIU survey editor.

The EIU had calculated the cost of a basket of goods over 133 cities in order to form arrive at the rankings.

Commenting on Singapore's position as the most expensive Copestake said, "Singapore's position is skewed slightly by the complex system for buying and registering cars as well as relatively high incomes, which means that it remains relatively affordable for many residents."

Asian cities, including Tokyo and Seoul secured 5 of the 6 top spots for the rankings. Zurich, placed 3rd in the study, was designated as the most expensive European city.