Emmanuel Macron is to push through sweeping reforms to France’s vast state rail system and cut rail workers’ special employment rights – tackling one of France’s riskiest political issues.

Any question of overhauling the SNCF state railway company has always proved controversial, with the train network grinding to a virtual halt for weeks when trade unions opposed changes to rail staff’s benefits in 1995.

But the French prime minister, Édouard Philippe, said that the government would quickly push through changes by special executive decree without a vote in parliament if necessary. Trade unions are discussing possible strikes on 12 March and will join bigger public sector strikes on 22 March.

Unlike Britain, where rail services were privatised in the 1990s, the SNCF remains state-run and is seen as a national treasure. But, although the train network has been rated among the best in Europe in terms of speed, quality and price, urban commuters and regional passengers increasingly complain of overcrowding, inefficiency, delays and problems.

The main issue for Macron is that the French state rail operator is struggling under debts of €46.6bn (£41bn) – bigger than those of a small country such as Iceland or Croatia, but still in line with the large debt of rail networks in places such as Britain, where the track operator, Network Rail, is facing its own financial woes.

The prime minister said France’s rail situation was alarming and untenable. “Whether or not they take the train, the French are paying more and more for a public service that works less and less well.”

The prime minister, Édouard Philippe, announcing reform plans for the SNCF on Monday. Photograph: Eric Feferberg/AFP/Getty Images

Unions had expressed fears of privatisation after an advisory report 10 days ago suggested turning SNCF into an autonomous company backed by public funds. Philippe insisted on Monday that privatisation was not on the cards. He said the SNCF would remain state-owned: it was part of French people’s heritage and “will stay that way”.

However he was firm on cutting rail workers’ special employment status. Many French rail workers have jobs for life and, in some cases, the right to retire in their 50s – a decade earlier than other public workers. Under government plans, these historical privileges would not be applied to new rail staff.

Philippe said France’s national railway company had to become more efficient before local and national passenger services open up to competition in coming years under European Union rules. But trade unions raged at the possible use of executive orders to force through changes – as used for Macron’s labour reforms last year. Jean-Claude Mailly, the head of the Force Ouvrière union, warned that using decrees would “pour oil on the fire”.

The government said the reform process would begin with a parliamentary debate in mid-March but in the event of wide opposition the assembly would not have a final vote.

The prime minister has said he would not close small local train lines, said to cost almost €2bn for only 2% of national passengers. This issue could now fall to regional authorities to decide.