Charity behind London project admits it has no idea how much the final bill will be

The Garden Bridge Trust has said it will be asking the public to help plug a 拢50m-plus funding gap so it can build the bridge.

The bridge has already risen 拢10m in cost to 拢185m but in the charity鈥檚 latest report and accounts the Trust says the costs could go up again 鈥 and admits it has no idea what the final bill could be.

The Trust said: 鈥淒ue to the hurdles still to be cleared and the ensuing delays the final cost could substantially exceed the formal estimate. Until the hurdles have been overcome and the subsequent programme refined we will not obtain a definite estimate. Nevertheless we have developed an update fundraising strategy that reflects the increased costs.鈥

A public fundraising campaign, the Trust said, 鈥渨ill offer a range of ways in which the public can get involved and support the project. This is expected to generate funds but also raise public awareness and support.鈥

It is also looking at setting up an Endowment Fund to help with the estimated 拢3m annual running costs.

Contracting joint venture Bouygues and Cimolai had been expecting to start construction this summer.

The news comes as the chairman of the Garden Bridge Trust admitted that the charity cannot be considered a going concern because there are too many risks associated with the scheme.

In report and accounts filed at Companies House, Lord Mervyn Davies said that trustees 鈥渁re unable to conclude that the Trust is a going concern and feel it only appropriate to flag these risks in this report鈥.

Davies said the main risks facing the scheme 鈥 and the Trust 鈥 were securing land on the South Bank, getting confirmation from London mayor Sadiq Khan to guarantee the 拢3m running costs promised by previous mayor Boris Johnson, plugging the current 拢56m funding gap and making sure it has enough promised cash ahead of planning consents running out at the end of year.

In his report, Davies admitted: 鈥淚t is hoped that these will be resolved over the months ahead but since a number of these matters are outside the control of the Trustees, they recognise that if this is not possible, they will need to considered the further delay to the project, and in a worst case scenario, whether the project remains viable.鈥

Construction work on the Thomas Heatherwick-designed bridge is already months behind schedule with the Trust being forced to rip up a previously stated timetable of starting on site last summer.

Under this plan, preparatory works were supposed to have started last spring with the scheme due to have been completed by summer next year.

The report added: 鈥淧rovision of the mayoral guarantee is also a requirement of our planning permission [local authorities have said they will not pay for the upkeep of the bridge] which will expire in December 2017. For construction to commence prior to this, remobilisation of the construction team will be required during early summer 2017.鈥

Davies also blamed a number of factors for the already announced hike in cost including the EU referendum, a change in mayor and the installation of a new prime minister. The Trust says it has 拢129m of funding in place 鈥 拢60m of which is taxpayers鈥 cash.

In the accounts, the Trust said it had spent 拢28.6m in the year to March 2016, up from 拢5m the year before. The bulk of this, just over 拢26m, was spent on pre-construction costs, while a further 拢1.6m was shelled out on fundraising activities. Operational costs came in at just over 拢423,000. Its income during the period was 拢39.2 million. The Trust said it was carrying forward funds of 拢15.6 million.

The number of salaried staff at the Trust was eight who shared 拢477,000 in wages with three people earning 拢60,000 or more. The salary of the highest paid staffer, who is not named, was between 拢110,000 and 拢120,000. It also paid out 拢465,000 in temporary and contracted staff.

The price for the project was originally estimated at 拢60m when it was launched three years ago. Back then it was expected to be completed this spring.