Tipner West in Portsmouth: Hampshire and Isle of Wight Wildlife Trust release new pictures of how Lennox Point could look

Hampshire & Isle of Wight Wildlife Trust and the RSPB, which have jointly campaigned against the Lennox Point super-peninsula proposal , said its work showed it was feasible to build housing without breaching legal protections.

‘Our architect’s concept drawings show it’s possible to have affordable and appealing housing at Tipner West without destroying these special wildlife sanctuary areas,’ the trust’s chief executive, Debbie Tann, said.

‘We do not believe Portsmouth City Council wants to be the first local authority to push for housing to trump nature and we certainly cannot stand by and let such a damaging “Portsmouth precedent” be set. If allowed, this would mean nowhere was safe for wildlife.’

In the wake of widespread opposition to the scheme from councillors to land reclamation, the council shelved its Lennox Point ambitions, although the option has yet to be completely ruled out from consideration, despite pressure to do so.

Council leader Gerald Vernon-Jackson said a return to the more scaled-back City Deal plans for the existing land, which would provide about 1,250 homes compared to 3,500, had proven more palatable.

Little progress has been made in recent weeks, according to councillors, although the council has set a timetable for having its draft Local Plan, including a proposal for the site, completed by the end of the year.

‘We have to make sure we do everything properly because only then can we go to to the government and say we can’t build the 17,700 homes the government has set us as a target,’ Cllr Vernon-Jackson said.

But he warned the scheme still faced a funding shortfall of between £20m and £40m, despite government grants, and that ‘an unpopular choice’ would have to be made to cover the cost.

And concerns have been raised by wildlife trust officials that city council officers are still focused on the land reclamation scheme.

In response, the trust has set four ‘red lines for nature’ which, it said, would undermine the existing legal protections – the Special Protection Area, Site of Special Scientific Interest and Ramsar designation if breached.

These red lines are:

- To take the Lennox Point ‘super-peninsula’ off the table for good,

- To avoid any direct damage to protected areas for nature,

- To mitigate indirect impacts to the protected areas, including replacing habitat at the firing range,

- To create space for wildlife within the Tipner West development.

Trust policy and advocacy manager Sienna​ Somers said any precedent set in Portsmouth could be used to justify further environmental damage elsewhere in the country.

‘We think it’s possible to build a community that meets all these requirements,’ she said. ‘We are realistic in knowing that homes will need to be built in Portsmouth, but the council has to be aware of the importance of these sites and how its decision could be reflected in other protected areas.

She said the development would have to be ‘denser’ than existing plans but that the concepts, produced by Influence Landscape Planning and Design in a bid to ‘move the council on’ from the super-peninsula, showed it was feasible.

RSPB head of policy and advocacy Alice Hardiman said she recognised the need to build affordable homes in the city but said ‘nature needs homes’ as well.

‘It’s increasingly clear that many in the council are not keen on destroying the mudflats for housing,’ she said. ‘However, the alternative options would still build over part of the legally protected sites.

‘The council must abandon plans to destroy the internationally important wildlife area and concentrate on a vision for the undesignated land instead.

‘It’s our belief that at the right level a new community could be created without concreting a wildlife refuge that’s also a great natural habitat which stores carbon.’

A petition by the two charities last year was signed by more than 24,000 people concerned by the council’s proposals and they have continued to urge people to raise concerns with city councillors.