And sources close to the shopping mall say the Savers store will be replaced by a pound shop.
The Job Centre is said to be opening up in a unit previously occupied by Toys R Us. It will be a temporary unit to allow the service to have a public-facing office in the town centre in response to the Covid-19 pandemic.
DWP officials say the office will be in addition to its long-standing offices in Crown Buildings, in Southam Road. Its media office said the department was exploring potential options to take premises on a temporary basis in various locations across the country.
Any new site would be temporary and in addition to existing provision.
"Because of the commercial nature of the negotiations we cannot share any further detail at this stage," the spokesman said.
In other information received by the newsdesk, it is suggested a discount store in the shopping centre, is to be replaced by a pound shop. Castle Quay's official office said it could not give us information and the newspaper would have to approach the individual tenants.
The Banbury Guardian has not been told which pound shop may be considering a unit at the centre and is awaiting confirmation.
The future of the Castle Quay shopping mall was the subject of much discussion following the February 22 Cherwell District Council budget setting meeting, after which the Green Party councillor for Kidlington East, Cllr Ian Middleton, called into question the local authority's wisdom in taking on the mall and its 'Waterfront' extension.
Castle Quay lost Marks and Spencer last summer and will see Debenhams close its doors within weeks after a final sale, following the easing of lockdown.
Mr Middleton, who has 30 years experience in the retail sector, said after the meeting: "There are very few retailers looking for those sorts of units at the moment and those that are, principally the 'big box' discount stores, will be looking for very favourable deals that are unlikely to be anything like what Debenhams were paying.
"Many of them already have a presence in Banbury anyway so it's questionable if they will be attracted into the scheme without some very large concessions on lease terms.
"Other options would be to divide the space for smaller retailers, but that depends on the physical layout and may be difficult to achieve effectively. Meanwhile the loss of rent and the council's liability as a landlord for void business rates is going to bring further pressures on finances that I'm not sure have been fully allowed for in current contingencies."
Cherwell District Council was asked for a comment on the information received but has not responded.