Buyers in around 30 per cent of English cities are almost certainly already too late to complete a purchase by March 31 and the end of the stamp duty holiday.

A property consultancy, The Advisory, says with only 21 weeks to go before the end of the holiday – including the lockdown starting tomorrow and then the typically-extended Christmas break – only 70 per cent of English cities have a strong chance of completing a sale before the deadline.

“Because it takes roughly 21 weeks for house sales in hot markets to find a buyer, accept an offer and complete the legal process, only house sellers that are already on the market – or lucky enough to be in an area where houses are likely to sell fast – will be able to secure a buyer and get their deal over the line before the deadline” warns The Advisory’s founder Gavin Brazg.

“Everyone else will no doubt face last minute chain collapses as buyers pull out of the deal or try to renegotiate their purchase price downwards” he adds.

There has already been widespread concern over whether the current backlogs for surveyors, conveyancers and local council search departments can be cleared to allow deals to be completed in time for buyers to benefit from the stamp duty holiday.

Last week a letter signed by 15 industry heavyweights ranging from leaders of agents to removal firms was sent to Chancellor Rishi Sunak seeking an extension to the holiday, either through a tapered end or by a simple longer period.

Sunak was told that the current surge in demand by purchasers was putting the market infrastructure under huge pressure.

The Advisory’s data is the latest weapon in the argument for an extension. Using its PropCast PropTech tool – which assesses the market in different locations – The Advisory has drawn up a table which you can see below.

The Advisory says the greater the sales success rate in a city, the greater the buyer demand and the faster property should sell – suggesting buyers could still make the stamp duty deadline.

In the table, GREEN indicates where over 50 per cent of properties on the market currently under offer, suggesting high levels of buyer demand and properties selling at an above average speed.

ORANGE indicates where 35 to 49 per cent of properties on the market are currently under offer, suggesting moderate levels of buyer demand and properties selling at an average pace.

And RED indicates where fewer than 35 per cent of properties on the market are currently under offer, suggesting low levels of buyer demand and properties selling at a below average pace.