Campaigner organiser Caroline Criado-Perez wrote to the institution requesting the decision to replace Elizabeth Fry with Winston Churchill be reversed, on the grounds that the action legally contravened the Equality Act 2010.
However, the Bank of England disagreed, and now the the co-founder of online database for female experts The Women's Room UK plans to launch a legal challenge against the Bank of England.
Criado-Perez told HuffPost UK Lifestyle: "The Bank's original response was not only patronising and dismissive, it also completely incoherent. They asserted that the duty under the Equality Act was not engaged by this decision, while at the same time claiming that they had, in any case, fulfilled their obligations under it.
"They also refused to provide any evidence of their supposed engagement with the Act, dismissively calling our fair request for the documentation surrounding the decision 'a fishing expedition'."
"I'm confident of winning because our leading counsel, who specialises in the Equality Act, is absolutely clear that the Bank has got the law wrong; it's a pretty clear cut case," Criado-Perez told HuffPost UK Lifestyle.
"The onus is on them to demonstrate that they have paid due regard to the specifications of the Act and they have categorically failed to do this."
"In order to comply with the Equality Act, you must be able to show the processes that you used to ensure your compliance. That the Bank has refused to do this is a very negative reflection on their regard for the Act and for equality in general."
What do you think of our ideas for future women on banknotes? Let us know your thoughts in the comments below.
Caroline Criado-Perez will be taking part in our HuffPost Conversation Starters panel on feminism, which is being held at Wilderness Festival.
The Huffington Post UK are proud media partners of Wilderness Festival. Check back here for more exclusive blogs, competitions and stories soon. For tickets to the event click here: www.wildernessfestival.com