Almost 50,000 people marched through Dublin yesterday in protest at harsh austerity measures designed to haul Ireland out of its financial crisis.

The marches came after a week in which an €85 billion (£72bn) bail-out loan was lined up and the Irish government set out a four-year plan of spending cuts and tax rises.

Although organisers had called for “family friendly” protests, a hard-core of activists broke off from the main march and led an assault on police outside the Irish parliament, Dail Eireann.

Protesters with their faces covered with scarves lobbed bottles, eggs and fireworks at police lines and burned posters of Taoiseach Brian Cowen.

Police managed to keep the protesters under control and arrested one man for throwing firecrackers.

The march was organised by the Irish Congress of Trade Unions (ICTU), which warned that spending cuts and tax rises “will do irreparable damage and turn this country into a social and economic wasteland”.

Protesters marched from the River Liffy to a rally at the General Post Office, the focal point of the battle between Irish Republican rebels and British troops during the 1916 Easter Rising.

Vicky Langan, 24, a single parent and student travelled to the protest from Cork with her three-year-old daughter.

She said: “I’m worried about my child’s future as an Irish citizen and I’m seriously considering leaving the country if things take a turn for the worse.”

Hospital porter Brian Condra, 39, said he would struggle to feed and clothe his three young children after the budget.

He said: “Brian Cowen said three days ago people should pull together. I think he has a neck because he is ripping this society apart. He’s destroying this country to protect the banks.”

Independent Socialist MEP Joe Higgins held a second, smaller rally under the statue of 19th century politician Daniel O’Connell. Higgins said: “Our plan is that the working class people of Ireland will not pay for a single cent of the tens of billion of euros that was strangled in bad debt.”

The drastic cuts lined up by the Irish government could see 25,000 public sector jobs axed – about one in 10 of the workforce. There will also be four years of tax increases and spending cuts. Details will be revealed in an austerity budget on December 7, when €6bn of cuts will be announced.

The Irish communications minister, Eamon Ryan, said he expected to reach a deal on a bail-out loan with the European Union and International Monetary Fund within 24 hours.

The Irish electorate appears to be losing trust in the government, which suffered a major blow after a by-election defeat to Sinn Fein last week, leaving it with a Dail majority of just two seats.

Sinn Fein candidate Pearse Doherty won the Donegal South West seat with a more than 39% share of the vote.