Dozens of firms have signed up to support the team on April 4 – the day before the historic Wembley semi-final.

More than 50 Co-op stores across Portsmouth and Fareham have agreed to take part in the day which will also raise money for the Tom Prince Cancer Trust, a charity dedicated to the memory of a young Pompey fan who died of bone cancer.

And Wendy Shepherd from Wilkinson, in Fareham, has cajoled her colleagues into donning Pompey shirts at the store in West Street on Blue Day – even though some of them are Saints fans.

She said: 'A lot of us know about the charity, and what happened to that young man was such a tragedy.

'We want to help donate some money to reduce the chance of it happening to someone else.

'We have a good group here so there should be plenty of money handed over – and if nothing else it's a chance to wear something different to work.'

Wendy and her colleagues Sarah-Louise Lang, 19, Cat Evans, 18, Matt Atkins, 27, and Tracey Jacobs-Hope, 40, have all committed themselves to raising cash on the day.

Mrs Jacobs-Hope, a security officer, said: 'There is a pretty even split between Portsmouth and Southampton fans here, so some people will be making an extra effort for the trust.

'But I really don't think they will begrudge it too much as cancer is something that can affect us all throughout our life.

'I hope Portsmouth get encouragement for their Cup run from this because it seems like the whole south is getting behind them.'

Ted Merdler from Southern Co-ops will be doing his best to make sure all of the area's stores take part on the day.

He said: 'We have been looking to do something for the community and this is the perfect chance for some light-hearted but worthy participation.

'We probably have a fair few Saints fans so we won't impose the Pompey kit, but they will definitely be able to leave the uniform at home and come to work in something blue.

'It's an exciting event for Portsmouth and there's a great feeling about the city.'