Despite long-term plans, which included the eventual extension to Rákospalota, future extensions to the M4 are uncertain. Tarlós's Fidesz city government eliminated funding for the second phase of the line after taking over from Demszky's government, and the European Union has refused to provide additional funds. Some critics claim that without the extensions the current state of the line amounts to "several hundred-million forints thrown out the window."
