Hackney mayor Phil Glanville has written to transport minister Jo Johnson asking him to clear up his position on the Network Rail arches sale.

Mr Glanville told Mr Johnson, who has met with campaign group The Guardians of the Arches, that he still had “serious concerns” over the plans to sell all 4,455 railway arches to one seller.

In June the mayor wrote to transport secretary Chris Grayling asking him to stop the sale, which is now imminent, and said Hackney Council would be interested in buying the borough’s 182 units.

Following reports Mr Johnson had said he would try to intervene in the sale to ensure profit was not the only factor, Mr Glanville said: “It is important given the level of concern from businesses in Hackney we have clarity on your ideas, what they mean in practice and how they can be shaped.

“I would still have concerns about an approach that does not fully explore local alternatives including tenants, workspace providers, local authorities or other consortia having the opportunity to bid for local arches.”

Mr Glanville added that it was not too much of a stretch to say the proposed buyers would prioritise as much profit as possible.

The Gazette was at the meeting when the Guardians of the Arches was formed in London Fields early last year to fight devastating rent hikes. The campaign is now aiming to stop the sale, and has since gone national with hundreds of members from across the country. It also has the support of the Labour party, the East End Trades Guild and the New Economics Foundation. The group recently wrote to Mr Johnson with 13 demands they wanted him to consider.

A Department for Transport spokesperson said it was considering the proposals from the Guardians, but added: “We are committed to the sale because it will enable Network Rail to better focus on running the railway and proceeds from the sale will be reinvested in the network.

“Rail arches have played an important role developing many new, independent and diverse enterprises, and we are determined to see small businesses continue to thrive on the estate after the sale is completed

“It is important to note though that all existing leases will transfer to the new owner, all current arrangements and minimum protections will remain unchanged, and the sale will support local businesses because of the greater investment a new owner will bring.”