Campaigners have hit back at National Grid (NG) after the company claimed an offshore option to its controversial pylon project would cost six times the amount of existing plans.

In a letter sent to East Anglian MPs, NG said offshore alternatives could amount to a total of over £7billion, while the current onshore option would stand at just over £1bn.

East Anglian Daily Times: National Grid calculations of the cost of various options - taken from the letter sent to East Anglian MPsNational Grid calculations of the cost of various options - taken from the letter sent to East Anglian MPs (Image: National Grid)

However, Rosie Pearson of campaign group Essex Suffolk Norfolk Pylons claimed such predictions were "wrong".

She said: "Instead of a fully offshore, strategic, grid that links wind farms and takes excess power out of East Anglia - which is the problem National Grid needs to solve - they have presented a convoluted and therefore very expensive option.

"In this proposal, power comes onshore to Norwich before being taken cross-country to the coast.

"Only then does it go offshore.

"Instead of listening to feedback that a strategic offshore grid is needed - something which benefits all consumers - National Grid has presented a half-baked option outside of any consultation process and without detailed costings and information.

East Anglian Daily Times: Rosie Pearson of campaign group Essex Suffolk Norfolk PylonsRosie Pearson of campaign group Essex Suffolk Norfolk Pylons (Image: Susan Lang)

"We maintain what we have said all along, the consultation needs to be re-run with full information and a 100% offshore option that links wind farms and exports excess capacity from the region must be presented."

The news comes after National Grid sent a letter to South Suffolk MP James Cartlidge admitting it had not consulted on offshore options.

Company chief executive John Pettigrew said the company had been "consistent on this point" and apologised "if this had been misunderstood".

However, Mr Cartlidge claims he was assured by company officials on July 18 that their consultation "definitely covered offshore options" and he would be sent "a detailed document of proof".

In response to NG's latest letter, the MP said he had "lost trust in the company".

“I was very disappointed to see that National Grid have produced exactly what I feared they would – effectively a ‘straw man’ line down the sea from Norwich to Tilbury which is not a serious alternative," he added.

East Anglian Daily Times: In response to NG's latest letter, MP James Cartlidge said he had "lost trust in the company"In response to NG's latest letter, MP James Cartlidge said he had "lost trust in the company" (Image: Office of James Cartlidge MP)

"They are clearly not interested in seriously considering offshore options, despite the many advantages they bring, and we need a fair assessment from an independent source."

A spokesman for National Grid said: “In response to feedback, we have published a letter to East Anglian MPs and offered a further briefing to explain and share our costs for the onshore and equivalent offshore options considered for the East Anglia GREEN project, which reiterates that an equivalent offshore option is more than six times the cost of an onshore option.

“The next phase of consultation in late Spring 2023 will include detailed information showing how we have developed the scheme in response to the feedback received, as well as providing greater detail on the route of the proposed onshore corridor and how we will be mitigating impacts on local communities living in close proximity."