The butchers of Smithfield Market have attacked the ‘disgraceful’ behaviour of conservation groups fighting plans by Thornfield Properties to redevelop part of the famous meat market in London.

At a public inquiry into the £200m redevelopment plans today the butchers accused English Heritage and SAVE of undermining the market and creating instability.

Greg Lawrence, chair of the Smithfield Market Tenants Association, told the public inquiry that for five years English Heritage and SAVE had: ‘proceeded in a manner that is designed to deliberately undermine the market by muddying the waters through innuendo and that is disgraceful in my opinion’.

Thornfield’s plans comprise replacing the disused General Market Building on the western fringe of Smithfield Market with a 480,000 sq ft office and retail development.

Lawrence, appearing today in the six-week enquiry, said the tenants’ association supported the development because it would regenerate the area and protect Smithfield as a working market. Unite, the union which represents market workers, has also backed the scheme.

He said English Heritage had shown ‘a disdain for the people that make Smithfield the thriving market that it is today. English Heritage, which is a public body, has sought, alongside SAVE to drown out the voice of the Smithfield butchers.’

English Heritage has dismissed Lawrence’s claims but said earlier in the six-week enquiry that Thornfield’s proposals were ‘dangerous’.

Mark Dodds, a partner at Development Planning Partnership, said Thornfield and the City of London should not be allowed to benefit because the local government has failed in its duties to maintain the buildings.

‘Neither the City of London nor the applicants should benefit from this situation,’ he said. ‘Such an outcome would set an unfortunate and dangerous precedent in respect of the proper stewardship of heritage sites.’

The inquiry closes next week. Ken Barton, the government inspector, will report to Hazel Blears,secretary of state for communities and local government who is expected to make a decision on the development in the summer.