Pompey have just 300 seats left in the Fratton end for this season.
That is the result of more than 9,200 fans snapping up season tickets since they went on sale two months ago.
The ‘early bird’ offer, along with the direct debit option, ends at midnight tomorrow.
Yet the club anticipate breaking the 10,000 barrier for the 2013-14 campaign which kicks off against Oxford at home on August 3.
In the meantime, the Fratton end is hurtling towards consisting solely of season-ticket holders and being sold out all season.
The current phase of seat sales ends at midnight tomorrow, with the Fratton Park ticket office open from 10am-2pm.
And engagement manager Mike Hall is urging supporters to take advantage of the current offers and get their Fratton end seats before it’s too late.
He said: ‘Season ticket sales are coming in left, right and centre.
‘Our message to the fans is don’t hold back and wait for a seat, especially if you want the Fratton end.
‘There are currently 300 left in that section and we expect it will be sold out by season-ticket holders before too long.
‘If you buy now you will get the best seats available anywhere in the ground.
‘And if there are better seats available next week we will change it.
‘The ticket office is open until 2pm, however it will probably stay open longer than that depending on the size of the queue.
‘You can still buy online on midnight, so the opportunity is there for everyone.
‘So get yourself a seat there now – do it today!’
Since going on sale on May 13, season-ticket sales have surpassed the 8,080 sold last term.
It reflects the feel-good factor which exists for Blues fans after the Pompey Supporters’ Trust took ownership of the club.
And now the club are focusing on getting to five figures.
Hall added: ‘We are really very confident we will get to the 10,000 mark.
‘New season-ticket holders is still running at 30 per cent and there is still under three weeks before the start of the season.
‘If we get 10-per-cent slippage on those who choose not to renew, that will still give us 20 per cent up on last year – basically more than 10,000.
‘You have to expect some not to renew – peoples’ circumstances change and we feel for that.
‘However, by the close tomorrow, we are hoping to have sold 9,500, which would put us in a strong position.
‘Then we need to sell 500 over the rest of July and the first few days in August to smash that 10,000 figure.
‘We are delighted with the amount of trust the fans have placed with us and would like to think we have rewarded them with a very competitive team.
‘Not only that but hopefully a vastly improved match-day experience.’