The public face of the Library of Birmingham – director Brian Gambles – is leaving the role after massive cuts were revealed.

Brian Gambles, aged 59, praised for steering the project through its development over the last decade, will retire early next year.

It comes after Birmingham City Council announced plans to cut the opening times from 73 to 40 hours per week and make more than half of the staff redundant - to cut £1.5 million from the £10 million per year running costs.

Businessman Keith Bradshaw, who chairs the Library of Birmingham Development Trust, said a new model of running the state-of-the-art facility – including perhaps offering naming rights to a major backers – is needed.

Mr Bradshaw said: “It’s a tragedy for the people losing their jobs, the librarians and archivists. It is also a tragedy for the city that we have this fabulous building and really great staff. We have to acknowledge that it isn’t easy for anybody.

“This is not a time for recriminations and finger pointing. We have got to make this the beginning of something better. There is a responsibility on all us to engage with that.”

He singled out council Labour deputy leader Ian Ward for staunch support of both the Trust and Library and said that they must now all pull together.

“The Trust will be looking at what might be possible, and everyone involved needs to look at how we can generate income and whether we need an entirely new structure.”

The Trust was set up to raise income for the Library, but has not managed to meet its target this year. There has also been criticism of the restriction placed on sponsorship opportunities, which if lifted may prompt a backer to come forward.

But Mr Bradshaw added: “A fundamental point is that we do not seem to be able to harness philanthropy, whereas you can go to the Library in New York and every brick is sponsored by somebody.”

The Labour cabinet announced this week that 100 jobs could go at the Library as part of the cuts. It said it cannot justify not only the £10 million a year running costs, but the £12 million a year repayments on construction. The costs have spiralled since 2007 when the development was launched - due to the lack of private sponsorship and the council’s failure to raise expected income from city centre land sales since the economic downturn.

The library cuts, part of the council’s 2015/16 budget proposals, are currently the subject of public consultation.