Updated 7.10 Adds new video.

Thousands of people are in Valletta taking part in the second protest in as many days against the increase in the utility tariffs.

They walked behind trade union leaders from City Gate to Palace Square, where the union leaders are presenting a letter to MPs as they enter Parliament, asking them to back an Opposition motion to revoke the new tariffs.

Police barriers stopped the people at Republic Street corner with the Palace Square but the union leaders were allowed through. A number of MPs entered the Palace before the union leaders arrived.

The MPs are being asked to reciprocate the trust shown in them by the people who elected them, by voting against tariffs which are causing hardship.

Insults were hurled by the demonstrators at Nationalist MPs, with the chanting of 'mafia mafia' and Gonzi purcinell.

Dr Gonzi walked in shortly before 6 p.m. as GWU General Secretary Tony Zarb and MUT President John Bencini handed him their letter and the crowd's chanting reached a crescendo.

The proceedings in parliament are being relayed to the crowd on loudspeakers, They booed when newly-elected Nationalist MP Peter Micallef was sworn-in at the opening of the sitting.

The union leaders are to follow the parliamentary debate from the Strangers' Gallery in the Chamber.

Today's and yesterday's protests have been organised by the Ghaqda Trade Unions Maltin, which is composed of 12 trade unions including the GWU, the MUT and the MUMN.