The owners of the Grosvenor Centre have set themselves a deadline of October 2017 to open the £350 million expansion to the town centre mall.
Insurance firm Legal & General, which bought the Grosvenor Centre in 1999 and revealed plans to expand the store in 2000, has faced a great deal of public criticism and scepticism because of the time it has taken to put together a firm plan to expand the centre.
But speaking to the Chronicle & Echo yesterday, the firm's retail development expert, Simon Russian, pledged a planning application for the development would be submitted next year with work on site expected to start in 2014.
He said: "We're talking to a number of big name shops at the moment and they think Northampton has got fantastic potential.
"They can see the town centre is punching below its weight and they all want a piece of it.
"And we've always been committed to the expansion project. These things do take time, but we're 110 per cent behind it. We've got massive faith in Northampton town centre."
Discussing the public cynicism which has developed around the project, he admitted Legal & General was partly to blame because it had failed to release details of behind-the-scenes talks which have been ongoing for the past few years.
He added: "There probably has been a lack of communication from us in terms of letting people know what's going on, but the plans have really got the wind in their sails now."
Latest plans for the scheme would see the Greyfriars bus station demolished in 2014 and the shopping centre extension built on the land it covers.
The extension would contain more shops than the current Grosvenor Centre and include a major department store.
Mr Russian said: "We hope it will be a real catalyst for the regeneration of the rest of the town centre. There's a very good degree of interest in Northampton town centre and in this scheme."
He also argued the current recession was not a stumbling block to the development, adding: "Because we're in a recession, it's a good time to be doing the planning work now, so we can hit the upturn going forward.
"People shouldn't expect to see cranes on site next year, but we want to make things happen as soon as possible. There has been a recession, but retailers do want new space in the town."
For exclusive artists impressions of what the centre could look like and more details on this story, don't miss today's Chronicle & Echo.