The projects are part of a backlog inherited by the Building Safety Regulator after building control firms AIS and Assent pulled out of the market a year ago.

Of the 10 legacy jobs now at Gateway 3, only one has been approved — freeing up just 336 homes for occupation. The rest remain in limbo, threatening to tip some developers over the edge as finance costs mount.

A residential scheme funder warned: “Progress on Gateway 3 is glacial. Developers are paying for finance months after they planned. Someone could go under if this drags on.”

On most legacy projects, work has continued at developers’ risk before Gateway 2 and 3 clearance. This has made the task of getting sign-off even more complex.

A spokesman for the regulator said: “BSR has had to pivot resources to look at Gateway 3 applications for new-build projects sooner than anticipated.

“We are undertaking a very complex task of assessing the design and build of projects for which we have had no prior involvement.

“BSR has an important role in these unique and complex projects to ensure that what is built is safe and compliant, and it must ensure that this is not compromised.”

These delays underscore growing industry concern that Gateway 3 could prove a real flashpoint for the industry.

A consultant said: “Imagine the cost accumulation on borrowed money alone for a large residential or student accommodation scheme that can’t be occupied for 30 weeks.”

Construction director at developer Olympian, Richard Goodwin, said: “We are looking at the death of design and build in terms of current working practice.

“Design changes are commonplace during construction but that has to change. Now all small changes must be notified and big changes submitted to the regulator for approval.

“In practice, this means design will be fixed at Gateway 2.

“The management of the change process is going to be critical for Gateway 3.”

Industry sources warn legal disputes are inevitable around missed deadlines, build quality, and spec changes — all of which could drag the regulator into courtroom rows.

As one insider put it: “This isn’t just red tape — it’s a wrecking ball for cashflow.”