PARIS, Nov 18 (Reuters) French postal and telecoms unions said today they would join a planned public sector protest on Tuesday as a transport strike headed into a fifth day amid a warning the action could start to hit factory output.
''In the absence of (freight) trains, factories, notably in the chemical and car manufacturing sectors, are going to be unable to work,'' Guillaume Pepy, an executive with state-owned rail company SNCF told Le Parisien newspaper in an interview.
Parisian shops and restaurants have already complained the rail strike has cost them lost business, although analysts say the macroeconomic impact of the strike has so far been limited.
The railway unions, who are protesting at planned pension reforms, are due to announce their next steps late today.
Despite a tentative offer of talks from SNCF and the government, the rail strike is expected to continue until Tuesday, when civil servants and teachers are due to march in cities across the country in their own protest over pay and conditions.
Opinion polls show the rail strike is unpopular with most French voters, but the government struggling to meet growth goals knows it cannot afford to let the protest drag on too long or risk a wider social conflict.
Twenty six universities remained blockaded by students on Sunday in a separate protest over education funding.
The CFTC union representing staff at La Poste and France Telecom said on Sunday it would join Tuesday's day of action, as has one union at airline Air France.
An opinion poll for Le Parisien newspaper on Sunday found most French people believe President Nicolas Sarkozy was best placed to tackle the strike, but the majority was slim.
Another poll for Journal du Dimanche found political support for the president down to 55 per cent, a drop of four points in the month and his lowest score since being elected in May.
Union leaders are in a dilemma too, because their members have so far signalled little willingness to negotiate.
''It's a strike that not many really wanted and, therefore, no one really knows how to get out of,'' Le Journal du Dimanche said in an editorial.
The SNCF said 250 fast TGV trains were due to run on Sunday compared with 700 on a normal day. Paris metro operator RATP said one train in five would run on most lines, while trains serving the capital's airports would be ''very irregular''.
The rail unions oppose plans to scrap special pension privileges that allow some 500,000 public sector workers to retire on full pensions after paying contributions for only 37-1/2 years, instead of 40 years for other workers.
REUTERS SZ KN1745