Angela Rayner, the communities secretary, has granted full planning permission for an asylum centre at a Ministry of Defence site near Piddington in Oxfordshire, despite local opposition to plans to house 1,256 detained asylum seekers there.

The decision approves plans for the refurbishment and redevelopment of the former barracks. However, the Home Office insists that its final approval is still required and a decision on whether to proceed has yet to be taken.

In September, people in Piddington voted to leave the UK in a symbolic referendum against plans to accommodate the asylum seekers nearby. A total of 285 people voted in favour of independence from the UK, while 26 voted against.

The poll was organised by campaigners to allow residents to demonstrate their opposition to the plans for accommodation at the converted MoD site near the town of Bicester.

A Home Office spokesperson said on Thursday: “Planning permission allows us to continue to progress the use of MoD Bicester. However, a final decision to proceed is yet to be taken.

“The government is working on a fairer distribution of asylum accommodation across the country, with over £1bn saved in costs since the election.

“This includes closing all asylum hotels and moving to alternative accommodation, including former military sites. These are designed to be self-contained, with 24/7 security and CCTV, to minimise the impact on the local community.”

There is now a six-week window in which the planning decision can be challenged through the courts.

A Ministry of Housing, Communities and Local Government spokesperson said: “The secretary of state has granted full planning permission for the temporary, phased use of the former MoD Bicester storage site.

“As the decision may be subject to legal challenge, it would not be appropriate to comment further.”

Last month, campaigners opposing the government’s plans took their complaints to the High Court.

The group Wrong Plan Wrong Site had sought a judicial review of the Home Office proposals for the former MoD Bicester site.

In August, the government concluded that an environmental assessment was unnecessary for the proposed development.