By Angelique Chrisafis in Paris, The Guardian–

French unions are staging a second round of mass street demonstrations as the country entered its sixth day of a nationwide strike and transport standstill over proposed plans to change the pensions system.

The government’s standoff with unions continued as the prime minister, Édouard Philippe, said he would stand firm and announce details of the pension changes on Wednesday, with speculation over possible concessions on the start date in order to diffuse growing tensions on the streets.

The government will be watching Tuesday’s turnout after being caught off-guard by the scale of last week’s protests when at least 800,000 people took part in one of the biggest demonstrations of trade union strength in a decade.

Crucially, the number of protesters has been particularly high in small provincial towns, echoing the mood of the gilets jaunes (yellow vests) anti-government protests earlier this year. People are angry not only with pensions but low salaries, worsening prospects, the state of public services and what one demonstrator called “the feeling of being forgotten”

One local MP for Emmanuel Macron’s party said it would be hard to tackle a protest movement that spread from pensions to several different grievances at once.

Across the country, transport turmoil continued on Tuesday with trains at a virtual halt, some flights grounded, 10 lines of the Paris metro closed and more than 180 miles (300km) of traffic jams on roads around Paris by 7am local time (0600 GMT). Teachers, hospital staff, fire officers, air-traffic controllers and other public sector workers were expected to walk out alongside train drivers and transport workers.

In the greater Paris area, where more than 9 million people depend on an already overburdened public transport system each day, there were dangerous crushes on packed platforms as crowds of commuters tried to push on to the very few banlieue trains running at rush hour.

Macron, the pro-business president who has promised to deliver the biggest “transformation” of the French social model and welfare system since the postwar era, regards his pension changes as a key test.

He has staked his political credibility on refusing to buckle in the face of street protests, accusing previous presidents of lacking the resolve to stand strong. With Macron potentially aiming to run for a second term in office in 2022, backing down would be to risk losing his support base. But protesters said they feared France’s social safety net was being unpicked.

a group of people standing around a bus: Union members and employees of the Paris transport network RATP block a bus depot in Les-Pavillons-sous-Bois near Paris. Photograph: Lucien Libert/Reuters© Provided by The Guardian Union members and employees of the Paris transport network RATP block a bus depot in Les-Pavillons-sous-Bois near Paris. Photograph: Lucien Libert/Reuters

The government argues that unifying the French pensions system – and getting rid of the 42 “special” regimes for sectors ranging from rail and energy workers to lawyers and Paris Opera staff – is crucial to keep the system financially viable as the population ages. But unions say the changes are an attack on fundamental worker rights, and fear people will have to work longer for smaller pensions.

Police ordered all shops to close on the route of the demonstration in southern Paris. Other big marches were planned in cities including Grenoble, Lyon and Rouen.

.