According to eyewitness reports on Twitter, the police are filming those who have already come to the rally. People are holding placards that read "Don't let the Tories wreck our lives" and "Humanity not austerity."
As many as 1,000 people confirmed their attendance on the march's Facebook page.
Last week, around 250 campaigners gathered in Cardiff to protest against the newly-elected government.
Cardiff is not the only city to have witnessed anti-austerity action since the May 7 elections. On Sunday, at least 15 people were arrested in London following clashes with the police in protests.
On May 7, general elections were held in the United Kingdom. The Conservative party won the vote after securing the absolute majority of the seats in the lower house of the British parliament, the House of Commons.
The five-year austerity program, implying substantial public spending cuts in Britain, was introduced in 2010 by the Conservative party. In their election campaign, the Tories claimed that the measures should be retained in order to eliminate the deficit.
