Workers have finally left a huge office block after plans to turn it into flats were given the green light.

The building's owners, Telereal Trillium, want to transform Becket House in New Dover Road, Canterbury into a residential complex.

The site had housed a BT call centre, but all staff have now left the building.

Telereal Trillium launched a proposal in 2017 to turn the prominent site into 118 homes – although the development is on hold while ecological issues stall new homes being made available.

The city council rejected the plans, for reasons including the loss of employment floor space in the city, the impact on the local economy and the effect of the proposal on two adjoining conservation areas.

The company appealed the decision but lost at a planning inquiry.

However, it launched fresh plans in 2020 to turn Becket House into 53 flats - a mix of one- and two-bed homes.

The firm made an application to the local authority to determine if it requires approval before going ahead with the conversion.

But city council officers ruled prior permission is "not required in this case".

This means the developer can go ahead with the works outlined in its application, which were resubmitted in 2021, and transform the offices into residential space.

But the building could sit undeveloped for years to come until the issues are resolved with water contamination at Stodmarsh which is restricting new development from going ahead.

Under the agreed permission for Becket House, development must begin within three years – meaning the application to convert the building expires next year.

"Any future redevelopment subject to planning permission..."

The government changed the rules several years ago so the change of use of offices to residential is considered to be a permitted development.

But landlords wanting to do this have to apply for 'prior approval' from the council before converting a building.

'Prior approval' allows a local authority to assess a number of implications the development would bring, such as transport impact, site contamination and flood risk.

An identical application was also permitted by the city council in 2014, but expired seven years ago.

A spokesman for BT says the building is currently leased to the firm but will be handed back to the landlord this summer.

"Our staff are no longer working at the site, with the majority moving out of the building in November, in preparation for it to be handed back to the landlord," he said.

"All colleagues had left the building by the end of March."

Telereal Trillium would not confirm when work will start or when it is expected to be completed.

A spokesman said: "I can confirm that this property is owned by Telereal Trillium with any future redevelopment subject to planning permission."

Becket House, a five-storey brick building, was built in 1939 as a telephone exchange, according to planning documents previously submitted to the council.

It was previously in part of the garden of Ersham House, which once occupied a large plot south of New Dover Road but has since been demolished.

It is understood the building was used in the Second World War as a military and civilian communications centre.

A large brick rear extension was built in the 1970s and extends southwards. The rest of the site is car parking.