The plans to rebuild Watford General will cost far more than the £400 million pledged by Prime Minister Boris Johnson.

West Hertfordshire Hospitals NHS Trust is in line to receive much needs funding to renovate its facilities and is focused on spending most of the money in Watford.

Proposals unveiled by the trust could see three new blocks, including a 17 storey tower, created next door to its current hospital site in Vicarage Road, with floorspace double the size of the current hospital.

However, there are question marks over whether the plans will be affordable, with the trust's deputy chief executive, Helen Brown, admitting she and her colleagues are "working hard to striking the balance between having fabulous new and refurbished buildings whilst pursuing good value".

In October 2019, Mr Johnson named West Hertfordshire NHS Trust as one of six "frontrunners" for funding to improve its facilities and pledged £400 million.

Last year, the trust received a letter from the Department for Health which indicated there may be up to £540 million to spend in Watford, along with £50 million at St Albans City and Hemel Hempstead hospitals.

However, the cost of rebuilding Watford and redeveloping the other hospitals is now "likely" to cost more than £590 million - and perhaps closer to the £650 million the trust estimated a redevelopment would cost in 2017.

The latest increase in cost estimates has been driven by the increasing importance of net zero carbon and the integration of the latest digital technology – as well as changes in response to the Covid-19 pandemic.

These additional costs would be applied to any hospital redevelopment.

The trust remains in the dark about exactly how much money it is going to receive, but it is in "close and active dialogue" with the New Hospital Programme and is still in the group of frontrunners - now known as 'pathfinders'.

Hospital bosses are currently putting together their outline business case to present to the Government in order to secure the funding.

Trust chief executive Helen Brown said: "We take the responsibility of spending public money very seriously and so, as we press on with our plans, we will also look for efficiencies.

"We are working hard to strike the balance between having fabulous new and refurbished buildings whilst pursuing good value.

"This is a once in a generation opportunity to transform the way we provide care and our sites and so we are driven to make sure we 'right size' our buildings and leave ourselves room to grow.

"We are continuing to work with the New Hospital Programme on our plans and how these impact on our costs, which we will share towards the end of this year when they are more fully developed."