Backers of the Open the Seafront campaign aim to march and cycle along Eastern Parade, which is not currently closed, from 10am on Saturday.
The protest was planned at a meeting at the Tenth Hole cafe, also in Eastern Parade, on Monday where more than 200 people discussed ramping up their opposition to seafront road closures.
It comes after the council closed parts of Eastney Esplanade and Clarence Esplanade indefinitely on May 1 to allow pedestrians to socially distance.
Campaign spokesman Mark Trapani, a former director of the car dealer Snows, said: ‘We're not going to be terribly disruptive – that’s not our aim and I don’t think any of us want to be seen in that way.
‘However what we do want to get across to motorists, cyclists and pedestrians alike is the fact this problem is making everyone’s life hell.’
Those attending Monday’s meeting voted on four options for the closed roads put forward by Portsmouth City Council’s leader, Gerald Vernon-Jackson.
Mr Trapani said ‘95 per cent’ of people voted for a total reopening, while three apiece opted to remove a row of parking in nearby Eastern Parade or reopen one lane of the esplanade.
One person, he said, voted to keep the closures in place.
But Mr Vernon-Jackson, who lives a five-minute walk from the cafe, claims he was not invited to the meeting and the vote was carried out incorrectly.
He said: ‘I asked them to rank the four options but they didn’t do that – the vote didn’t tell us anything we didn’t know before.
‘It’s so difficult to work with people not interested in compromise and come up with a suitable solution.
‘I absolutely recognise things are more difficult for people in Eastern Parade but the plan is to reopen the seafront in September – that’s just a couple of weeks away.’
He added: ‘I do hope people are going to [protest] in a way that’s safe.’
The demonstration has been backed by David Moore, who owns the Tenth Hole and said the cafe will be open as usual on Saturday.
He said: ‘Although I shan't be in the march I think democracy needs to play its part.
‘This situation cannot be any worse than it has been over the past two weekends – the traffic has just ground to a halt.
‘From a business point of view, there may be a bit of short-term aggravation for a long-term benefit.’