English MPs are calling for their own regionally devolved reforms to Stamp Duty Land Tax after Scotland detailed its own plans last week.

Scotland is to replace SDLT with a new “winners and losers” Land and Buildings Transaction Tax next April.

But concerns are mounting among agents and lawyers that the housing market in Scotland now faces huge distortion – with some buyers trying to delay transactions in order to pay less, and others scrabbling to beat the deadline.

Richard Loudon, of Simpson & Marwick, a solicitor estate agent firm in Edinburgh, warned: “This is really going to throw the market into disarray. There is mayhem ahead.”

The new tax will start on homes which sell for over £135,000. It will charge only on the amount above this threshold, and not the entire value of the property.

It does not get rid of the so-called “slabs”, charging 2% on homes up to £250,000, 10% on homes up to £1m, and then 12%.

At a purchase price of £175,000, £950 less tax will be paid; at £400,000 the tax will increase by £5,300; at £700,000 the increase will be £19,300; at £1m by £37,300; and at £2m there will be an increase of £97,300.

So while those buying cheaper homes up to £325,000 will pay either nothing or less than now, anyone buying a home worth more than £325,000 will pay more.

For example, someone buying a £1.5m house would pay £137,000 as opposed to the current tax of £75,000.

Loudon said that he was concerned that the April 1 date of implementation related to completed transactions and not to “missives completed” – the Scottish equivalent of exchange of contracts.

He said: “This really is going to throw the market into disarray.  We have already had a lot of owners of prime properties contact us to put their property on the market before Christmas rather than waiting until the spring.

“It will be mayhem in March, and chain management will be virtually impossible.

“Buyers below £324,000 will be trying to delay completion until after April 1, whilst purchasers above £324,000 will be desperate to complete pre-April.

“Inevitably there will be deals that fall out of bed, with buyers not being willing to commit until the absolutely last minute and then a mad panic to try to get funds from lenders, removals, etc.

“Our advice to buyers and sellers above £324,000 is obvious: transact now and settle well before April 1.”

Estate agent Michael Luck, of Slater Hogg and Howison / Countrywide told the Glasgow Herald: “This is a tax on the already-squeezed middle. It will be good for first-time buyers, but beyond that it is punitive.”

Austin Lafferty, a director of Glasgow Solicitors Property Centre, said: “This is victimisation politics. At a balancing point of £325,000, perfectly ordinary individuals, couples and families will be penalised for bettering themselves.

“These are not fat cats, they – we – are contributors to the Scottish economy.”

Seemingly oblivious to the mounting criticism, a number of Westminster MPs said the Scottish reforms showed it was time for a regional system of SDLT and called for similar reforms in England.

Dominic Raab (Tory, Esher and Walton) called for SDLT to be scrapped for all homes in London costing less than £500,000.

Anne Main, Conservative MP for St Albans, where home buyers pay more SDLT than any other constituency outside London, said: “What the Scottish proposals now show is that it is untenable for current thresholds to remain in place.”