Farmers must stand united and resist British Sugar's efforts to divide growers, said Norfolk's county delegate Richard Hirst.

At the East of England showground last week, they had voiced clear backing for the National Farmers' Union's sugar board, which has rejected an offer of £30.67 tonne for the 2014 crop.

British Sugar's decision to write to growers inviting them to complete on-line contracts has annoyed growers' leaders. Robert Law, vice-chairman of the NFU's sugar board, said that the monopoly processor has so far refused to talk. 'Our message to growers: Stand United. Stand Firm.'

'They're not communicating with us, they're not talking to us. If they want bad relations with growers and more trouble next year, they're going about it the right way,' he added.

The NFU's sugar board was legally the only body able to negotiate for all 3,500 growers – whether or not they were NFU members,' said Herefordshire farmer Mr Law. 'We want to sit down and engage with British Sugar to talk through this and move it on,' he added.

In a letter to growers, sent on the final day of the Royal Norfolk Show, British Sugar said that it had to offer a contract by Sunday, June 30 to comply with the IPA (inter-professional agreement). Contracts had to be returned by July 31, it warned.

Mr Law said that British Sugar had not asked the NFU to consider a delay or even hold talks. 'We're dealing with the worst excesses of a monopoly at the moment. The way that British Sugar are going about it is going to lead to a scrap which will cause further ill will and create bad relationships with growers,' he added.

Colm Mackay, British Sugar's director of agriculture, announced the offer at Cereals 2013 in Lincolnshire. In summary, a £3 tonne ex-gratia guaranteed payment will be made above the contracted beet (CTE) and industrial beet (ICE) price in 2014. He wrote that actual payments will be £30.67 tonne plus late delivery allowance.

Average payment in 2014 including LDA will be £31.15 tonne.

Industrial beet will be £30.67/tonne plus LDA.

Guaranteed minimum price of at least £25 tonne for any surplus beet.

Broadland farmer David Murrell, who has a 4,000-tonne contract, said that 'growers must not panic' and complete contracts. Growers at Peterborough said that a future beet price must recognise the costs of growing the crop, which had not been the case for a number of years.

'If growers don't sign or walk away from the crop then British Sugar won't get the crop grown. We have to stand firm,' he added. And looking over the fence, he said that the dairy sector had stood united.

The NFU said that the 350 growers represented 2.8m tonnes of beet - 35pc of the contract tonnage had made their position clear. The sugar board chairman, William Martin, who farms at Littleport, said that growers were fed-up with receiving a price, which was the lowest in Europe.

Ruth Digby, chief sugar adviser, said based on British Sugar's accounts, the NFU forecast an operating profit of £216m. Affordability is not an issue, she said.

Mr Hirst, of Ormesby, near Great Yarmouth, criticised British Sugar's attempt to 'divide' growers. 'It is an extraordinary way to go about things.'

British Sugar can afford to pay more for beet, the NFU's Ruth Digby told growers last week.

It made an operating profit of £29.67 per tonne having paid growers an average £27.53 tonne.