There has been uproar in response to a lengthy consultation on the government’s plans to split English Heritage, with nearly 600 replies querying the viability of the controversial plans.

The plan is to to make the body completely self-financing, no longer reliant on tax-payer support, with English Heritage becoming an independent charity responsible solely for the management of 440 historical sites including Stonehenge, Dover Castle and Hadrian’s Wall.

The rest of the organisation’s operations would remain within the UK government and be renamed Historic England but the plans have not gone down well with a lot of respondents airing queries or making demands, according to The Independent, which gained access to an early analysis of the responses, from a range of heritage organisations, developers and local authorities.

One respondent said the proposal as it stands “does not give confidence”, while others accused it of being a “hurried development” and said the financial assumptions made initially were “unconvincing.”

The document outlines the early findings of the consultation and acknowledges a series of questions over the finances supporting the potential split and what would happen to properties that were not financially viable or on the verge of collapse.

One key issue highlighted was a lack of clarity on what would happen to English Heritage and its 440 sites if it failed to achieve the proposed aim of becoming self-sufficient.

The Institute for Archaeology (IFA) commented in an open letter that the government had failed to provide enough detail to give confidence that English Heritage as a charity can become self-funding in the eight year period outlined.

IFS chief executive, Peter Hinton, also wrote that “the absence of any contingency planning in the vision is a real cause for concern”.

The government is planning to give £80m to English Heritage to allow it to carry out major refurbishment across its properties and to help launch the charity, but some respondents do not believe that the sum of money is large enough.

English Heritage chief executive Simon Thurley has called the split “the only way forward” and said that in principle, the majority of respondents were in support. The Department for Culture, Media and Sport is currently compiling a detailed response to the consultation and will be publishing its findings by summer 2014.