Southeastern has published a consultation document ‘Shaping the Future’. At 46 pages long you would be forgiven for missing the lines on page 23 which say: “There would be a limit to the improvements that could be made to the timetable without also reducing the number of central London stations served from certain locations at particular times. An example might be for all Metro services on the north Kent (between Dartford and
Charlton), Greenwich and Bexleyheath lines to terminate at Cannon Street only. We believe that the simplicity of a regular service to a single London terminal throughout the day would benefit both regular and occasional passengers.”
If you travel on the Bexleyheath line to Charing Cross or Victoria you would be advised to complete the online survey as a response to this consultation. The DOCUMENT is here: https://www.gov.uk/…/south-eastern-rail-franchise-public-co…. The SURVEY is here: http://www.smartsurvey.co.uk/s/QHQQM/

There is also an online petition https://petition.parliament.uk/petitions/190894 but the important thing is to complete the survey and make your feelings known.