SCOTTISH pub campaigners have called for legislation which will radically alter contracts between landlords and tenants to be brought to Scotland, as the UK's biggest pubcos saw millions wiped off their stock market value in response to the changes.

Shares in both Punch Taverns and Enterprise Inns, which lease nearly 10,000 pubs to tenants around the UK, plunged after MPs voted to support an amendment to the Small Business, Enterprise & Employment Bill at Westminster.

Punch saw about £57.4 million wiped off its market capitalisation after shares dropped by 16.8 per cent to 126p, while the stock market worth of Enterprise fell by £121 million after its share price plummeted by 16.65 per cent to 102.6p.

With the share price of Greene King and Spirit Pub Company also falling, the market value of four of the biggest pub companies fell by in the region of £400 million.

MPs supported an amendment tabled by Leeds MP Greg Mulholland, which effectively frees pub tenants to seek an open market review to establish how much rent they pay to their landlords.

The amendment also ends the controversial beer-tie - a mechanism in pub lease deals which compels the tenant to buy beer from their landlord.

Tenants have long argued that the tie makes them uncompetitive because it forces them to buy beer at inflated prices.

At the same time tenants claimed their trading position was undermined by being unable to negotiate the rent they pay to landlords on the open market. Those constraints have now been lifted.

The changes affect pub companies with more than 500 tenanted outlets in their portfolios.

At this stage, the proposed legislation will not apply in Scotland, where there is estimated to be around 1,000 pubs leased from pubcos. However, having secured the support for the amendment for the six SNP MPs at Westminster, Scottish pub campaigner Lynn Adams will be pressing for the Bill to be introduced in Scotland after it gets Royal Assent.

Ms Adams, who leases the George Bar in Hamilton, described the Commons vote, which saw the motion carried by 284 votes to 269, as a "great result" for pub tenants.

She said: "The next stage for us is to go to the Scottish Government and ask them to use their enabling powers to piggy back on to it, probably through something like a legislative consent motion.

"I believe we have leverage with that as well, given that the six SNP MPs voted for it down in Westminster.

"I'd like to think that would carry a lot of weight."

But while tenants groups rejoiced there were dire warnings from the pubcos, which claimed it would hasten outlet closures and spark thousands of job losses.

Punch Taverns, which leases some 170 of its 4,000-strong estate in Scotland, said the amendment runs counter to UK Government proposals for statutory regulation of the sector.

It noted that ministers did not support ending the tie in its proposals for regulating the sector, announced in June following a lengthy probe by MPs on Business, Innovation and Skills Committee.

And it said the amendment ran counter to the conclusions of the Office of Fair Trading (OFT), which in response to a super-complaint from CAMRA (Campaign for Real Ale) in 2010 found that tenants "were able to compete effectively and that the commercial interests of pub companies and their tenants were aligned."

Punch said: "The Government's proposals did not include a mandatory free of tie option for tenants on the basis that it would have been likely to cause a high degree of uncertainty in the industry and would have unnecessarily risked leading to higher levels of pub closures and job losses."

Enterprise Inns, which leases the vast majority of 5,500 pubs in England, said the amendment "threatens to have serious unintended consequences for publicans and the industry at large".

Chief executive Simon Townsend said: "This amendment is a disproportionate response which proposes fundamental change that is wholly contrary to the findings of the consultation, from which the Bill was drawn up."

Paul Waterson, chief executive of the Scottish Licensed Trade Association, said the group backed moves to remove the beer tie and allow tenants to seek open market rent reviews in Scotland.

He said: "We're all for it. A lot of tenancies are in real trouble.

"It used to be the case at entry level that the rents were low, and you had to buy your beer from the owner of the premises. What happened over the years was that they kept the price of the supplies up, so you were paying a lot of money for your supplies, but the rents all went up too."

It is understood pubcos may mount a legal challenge to the amendment.