People Before Profit is proposing additional spending of €35.9 billion in its alternative budget, combined with €36.3 billion in revenue-raising measures.
The party is proposing free childcare, a state construction company and a wealth tax on the top 5% of households, among other measures.
Corporation tax would increase to 20% for large corporations.
There would also be four new tax bands for those earning over €100,000, which the party believes would raise €3 billion.
Child benefit would rise by 20% and headline social welfare and pension rates would increase to €300 per week, with an additional €50 cost of disability premium.
Richard Boyd Barrett said that People Before Profit's budget was the most responsible budget, compared to those put forward by other parties.
Read more: Budget will focus on cost of living, says Tánaiste
He said his party was seeking to redistribute wealth across society.
People Before Profit said it would also abolish the carbon tax, in favour of a commercial aviation tax.
The abolition of M50 and Eastlink Tolls is proposed to reduce the cost of living, city centre traffic and air pollution.
It believes it could double the delivery of social and affordable housing.
