The biggest purpose-built winery in the country has opened with a target to produce more than a million bottles a year.

The Rathfinny Estate in Alfriston wants to rival Champagne with its high-end sparkling wine.

Business secretary Vince Cable officially opened the £10 million, 160-acre estate, which is nestled in a ‘secret valley’ of the South Downs.

It is hoped Rathfinny will produce its first harvest later this year, with the first batch of wine to be ready in 2017.

It will sell at around £25-30 a bottle with half to be exported to America and Asia.

The estate already employs 14 staff and will take on a further 30 full-time staff and 200 seasonal workers.

Mark Driver, owner of the estate, said: “It’s always sunny in Rathfinny.

It’s a benefit of being so close to the sunniest place in the country, Eastbourne.

We’re blessed with the climate.

“Here in particular we’re on chalk with the perfect climate and a nice slope. We looked at various areas in Sussex but this was just most perfect.”

Mr Cable helped owners Mark and Sarah Driver secure planning permission after being initially refused.

He said: “One thing I value is seeing entrepreneurial companies creating employment.

“The groundwork was done in the depths of recession and it requires real courage to launch in such difficult conditions.

“Food and drink is now our biggest manufacturing industry in terms of creating skilled jobs and this is in a coastal area with serious pockets of unemployment.

“This is a creative, imaginative industry which is also good for exports.”

The Romans are thought to have grown vines in the area some 2,000 years ago.

Sussex wine dominated the recent International Wine Awards, taking home 25 awards including two gold trophies to Nyetimber and Breaky Bottom.

The chalky geography and seaside climate are similar to Champagne, allowing comparable bubbly to be produced.

Meanwhile climate change makes growing grapes like chardonnay, pinot meunier and pinot noir in southern England much easier.

Mark Driver gave up his job as a hedge-fund manager and bought the farm in 2010, investing £10 million of his own money.

He hopes to make a return on the investment in 2018 but does not expect to make a profit before 2020.

Mr Driver honed his knowledge studying viticulture at Plumpton College, part of the University of Brighton.

The environmentally-friendly building at the estate was short-listed for a RIBA architectural award with a curved roof that fits in with the landscape.

It will be energy and water self-sufficient with an underground treatment plant to deal with three million litres a year.

So far 64 hectares of the estate have been planted with vines.

Chief winemaker Jonathan Medard is a Champagne native, described as having “bubbles in his blood”.