Labour leaders in Portugal described a general strike on Thursday as the biggest in more than 30 years as disaffected youth joined traditional trade unions to protest at harsh austerity.

The 24-hour stoppage came as Fitch cut Portugal’s sovereign debt credit rating to junk status, citing the country’s adverse economic outlook, fiscal imbalances and “high indebtedness across all sectors”.

The strike was called ahead of a vote in parliament next week on what the government has acknowledged will be the country’s harshest budget in living memory, cutting the income of many public sector workers by as much as 25 per cent from 2010 levels. The scale of protest reflects the pain inflicted by the fiscal adjustments required under Portugal’s €78bn ($104bn) financial rescue programme.