The Bank of England says the Cumbria-based the supplier of its new £5 note is looking at "potential solutions" following criticism over the use of animal fat during the production process.

The Bank said it was "aware of some people's concerns" about traces of the derivative, known as tallow, in its polymer note since being introduced into circulation in September.

It said it was treating the concerns with the "utmost respect" and was in discussion with its supplier, Wigton-based Innovia.

In a statement, the Bank said: "This issue has only just come to light, and the Bank did not know about it when the contract was signed.

"Information recently provided by our supplier, Innovia, and its supply chain shows that an extremely small amount of tallow is used in an early stage of the production process of polymer pellets, which are then used to create the base substrate for the £5 note.

"Innovia is now working intensively with its supply chain and will keep the Bank informed on progress towards potential solutions."

Fury among vegetarians and vegans erupted following confirmation by the Bank that the notes contained tallow.

Keswick man Doug Maw, who started a petition against its use, said he was "disgusted" a more suitable alternative had not been sourced.

Mr Maw, a 47-year-old hotel worker said: "There is no excuse for it. There has got to be other ways of making money without using animal products."

More than 100,000 people have since signed the petition.

The £5 note, featuring Sir Winston Churchill, entered circulation in September.

It is printed on Innovia Security's Guardian material, a flexible plastic film. Those in circulation were not made in Wigton as the new plant was not finished, instead made using material from Innovia's Australian factory.

Any future prints and production of the polymer for the new £10 will however come from the Cumbrian factory.

Innovia has invested £40 million at Wigton to gear up for the Bank of England contract, including construction of an opacification plant to coat the polymer prior to printing.

Chief executive Mark Robertshaw says the note allows for a "new generation of cleaner, safer and stronger banknotes with robust security features".

Other countries using Innovia’s polymer include Australia and Canada, where counterfeiting rates decreased by 98 per cent after the introduction of polymer notes in 2011.

The Bank of England is plans to introduce a £10 polymer note next year, followed by a £20 polymer note by 2020.

Innovia is in the process of tendering for the £20 note contract.