Land Securities, the property group, has accused London law firm Fladgate Fielder of blackmail and is claiming at least £10 million in damages.

In a lawsuit filed at the High Court, Land Securities alleges that Fladgate launched a bogus judicial review in order to pressurise the property group into contributing towards the law firm’s relocation costs.

Fladgate’s judicial review, filed last month, is seeking to challenge Land Securities’ plans to re-develop an office block opposite the law firm’s headquarters that it says would have a “detrimental” affect on its business.

But according to Land Securities’ claim: “The applications for judicial review were issued for the predominate purpose of extracting from [Land Securities] assistance through financial contributions or otherwise to enable or facilitate a relocation of [Fladgate Fielder’s] business.”

Land Securities has accused the firm of having an "ulterior motive" and abusing the judicial review process.

It is seeking damages in excess of £10 million plus interests and costs.

Fladgate declined to comment although it is understood to be planning to defend the claim.

The dispute concerns the proposed redevelopment of Park House, a derelict 1960s office block on Oxford Street.

Neither side would comment on events leading up to the court filings but it is understood that discussions concerning possible changes to the planned development did not produce an agreement.

Mike Hussey, managing director of Land Securities’ London portfolio, previously told Property Week: “They [Fladgate] wanted us to pay for them to move and now they are using a judicial review to stop [the development].”

* Update: An application by Fladgate to have the claim dismissed was granted in the High Court on March 24, 2009.

Judge Bernard Livesey, QC, dismissed Land Securities’ claim, finding that there had been no abuse of the court’s process by Fladgate in opposing planning consents. Land Securities was ordered to pay Fladgate’s costs.

Fladgate said: “Our position throughout has been directed solely at securing the protection of our property interests.

"We are delighted that in standing up to one of the UK’s largest property companies, we have been fully vindicated by the court in the steps we took to protect the firm.”

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