Buying new trains would cost HUF 90 billion, Tarlós said, whereas renovating the old Soviet-made carriages would cost HUF 60 billion.
The government, which must give the local council permission to take out any loan for the renovation, is expected to take up the question at a cabinet meeting on Wednesday, he said.
Tarlós dismissed a report that he had negotiated with Russian President Vladimir Putin a week earlier on replacing the trains, but did confirm that he had discussed the matter with Prime Minister Viktor Orbán in a meet last week.
The trains on line no. 3 were made by Metrovagonmash.