Work will begin on a new neonatal intensive care unit at Bath’s Royal United Hospital in May after it received more than £500,000 from a Wiltshire-based charity.

The James Dyson Foundation, of Malmesbury, donated £333,000 towards the ‘space to grow’ campaign, following Lady Deirdre Dyson’s visit to the unit last week.

The hospital’s fundraising team, the Forever Friends Appeal, has received more than half a million pounds from the foundation and personal donations from Sir James and Lady Dyson, over the past few years.

NICU matron Debbie Grant said: “It’s really exciting for us. We are really pleased with the huge amount of work that the Forever Friends Appeal have been doing to raise the money for the unit.

“We are delighted that work will start in May.”

Alina King, 35, of Calne, had premature twins two weeks ago, born at 34 weeks, who are now in the unit. She said: “I’m here every day with all the other mothers and fathers and see what they are going through. The unit is very cramped but I think they are making the best of the space. I can’t wait to see the new unit open.”

She said she plans to come back with her twins William and Oliver and her partner Alex Cromb when the unit is opened.

The unit will be known as the Dyson Centre for Neonatal Care.

Lady Dyson said: “The new centre, built for the families of the future, is a wonderful cause to support.”

The unit also received a grant of £250,000 from the Garfield Weston Foundation (London), which will be used for specialist equipment.

The campaign still needs to raise £650,000 to help complete the build by summer 2011.