A number of protests took place outside Leinster House tonight.
Gardaí estimate that between 300 and 500 protestors were involved in the demonstrations, which began before the Budget speech was delivered.
The protestor numbers were bolstered this evening, when two marches organised by various left wing groups arrived at Kildare Street.
A large number of gardaí are present and Kildare and Molesworth streets are closed to traffic.
Three people have been arrested for public order offences. Two men are still being held, while one man has been released without charge.
A large contingent of protestors broke away from the crowd at the front of the Dáil and protested outside the gates of Government Buildings on Merrion Street.
This morning, a man was arrested after staging his own protest using a mobile crane.
Unions and groups have meanwhile been reacting to Budget 2011.
SIPTU has said that the budget claims growth figures which are not credible, insulates the rich and targets low and middle income earners.
General President Jack O'Connor said: 'In his budget speech the Minister for Finance, Brian Lenihan, cited projections of average growth of 2.75% per annum between now and 2014.
'Yet nothing in his presentation today supports these figures. There is no provision, of any substance, for investment or job creation.'
Unite condemned the Budget as a savage and undemocratic attack on people who the Government think will not fight back.
It said the Government had 'sought to right the wrongs of the bank leadership's criminal misadventure by taking €40 per week off workers on the minimum wage.'
Mandate accused the Government of scapegoating lower and middle income workers.
It said that despite having no mandate left, the Government seem determined to press ahead with making swingeing cuts to the minimum wage and to welfare which will devastate the lives of the people on the margins of society.
There was also criticism from IMPACT, which said the Budget would disproportionately hit the living standards of those on low and middle incomes.
Conceding that the scale of adjustment in the budget was required, employers' group IBEC said this could have been done in a way that was less damaging to economic growth and employment.
The group said the budget focused too heavily on raising tax revenue and cutting capital expenditure. It said more should have been done to reduce current expenditure, which remains too high given the major fall in tax revenue.
The Construction Industry Federation has expressed concern for employment and activity in the construction sector.
Chambers Ireland said that despite the Government’s commitment to cost-containment, Budget 2011 was a missed opportunity to provide many Irish businesses with the pro-enterprise measures they need during these harsh economic times.
Meanwhile, IFA President John Bryan said the changes to the tax and PRSI egime would impact negatively on every household in the country, and would be particularly harsh on low-income families, many of whom are in the farming sector.