The city is one of 15 across the UK to be shortlisted as a potential venue for the tournament in 2018 or 2022.
City officials went to Wembley yesterday to meet members of the Football Association as they launched a campaign to host the World Cup.
Portsmouth City Council leader Gerald Vernon-Jackson said: 'They know the situation with Horsea Island and they are still very keen.
'The FA is very enthusiastic about Portsmouth – they want somewhere south of London and at this stage we are the only city south of London that is being considered. It would be a great thing for the city and we have a good record of being able to manage big events.'
Fifa has said around 12 stadiums will be needed with a minimum of 40,000-seater capacity.
FA Chairman Lord David Triesman said he wants the bid to be made up of locations across the country – not just the big Premier League teams.
Pompey's chief executive Peter Storrie, pictured below, said the club could revisit plans to build a 40,000 or 45,000-seater stadium at the Horsea Island site, next to the M275, if the city was selected as a World Cup venue.
And Cllr Vernon-Jackson said if Pompey pressed ahead with plans to rotate Fratton Park and expand it to 30,000 seats, temporary seating could be added to increase its capacity.
But he warned that the city would need the full support of the club.
'The issue is that if we go for this then the contract is between the FA and the city council, not the FA and the football club,' he said.
'We would have to be very careful about entering into something that could have financial penalties if we don't deliver.
'We have all been waiting for 30 years for a new ground to be built and nothing has happened.
'If we are committed to providing a 40,000-seater stadium we would have to provide it, and the problem is we have no ability to deliver without the football club.' Cities will find out whether they have been listed for matches in December 2010.
Mr Storrie said: 'This will be great for the south of England.
'The city has great transport links, with Southampton and Gatwick airports close by, and there are great attractions in the wider area.'
CONFIDENT OF WINNING APPROVALExecutive chairman Peter Storrie last week revealed that work to redevelop 100-year-old Fratton Park could 'physically start' by the end of the year, although a planning application is yet to be submitted.
Mr Storrie said he was confident Portsmouth City Council would give the stadium project the go-ahead.
A new supermarket next to the ground – believed to be a Tesco – will fund 70 per cent of the £22m stadium scheme.
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