The service was listed for closure in the 1963 Beeching Report, with losses claimed as being £69,000 per year (). It was saved after a huge campaign. The line was Grant Aided under the Transport Act 1968 and came under threat when the Conservative Government of 1970–71 proposed to reduce Grant Aid funding. That threat, eventually lifted, led to the founding of a new campaign group, the North London Line Committee, which tried to work with British Rail management to promote the service.