Opposition Leader Simon Busuttil is not talking about the Gozitan works-for-votes "racket" because he is covering up for his own shortcomings, Prime Minister Joseph Muscat said this evening.

Addressing a political rally in Gzira, one of the localities up for Saturday's local council elections, Dr Muscat said Dr Busuttil was not being upfront with the scandal.

The alleged racket was uncovered by a Gozitan whistleblower last month and revolves around Gozo minister Giovanna Debono's husband Anthony, who employed contractors to carry out works for constituents using public funds.

Repeatedly referring to Dr Busuttil as "Mr Transparency", Dr Muscat said the Opposition leader had been avoiding the press for several days.

Dr Muscat said there were glaring contradictions in the version of events given by both Dr Busuttil and Nationalist Party general secretary Chris Said as to when they first found out about the scandal.

PN party president Anne Fenech had also given a different account of when the party's top brass had come to know of the scandal, while deputy leader Beppe Fenech Adami declined to comment on the matter, he added.

"The Easter holidays are over and Mr Transparency hasn't risen yet. He is hiding from speaking about this racket, not to protect [Ms] Debono or [Dr] Said, but to cover up for himself and his shortcomings," he said.

Earlier during the rally, Dr Muscat spoke about the Metropolis Plaza, a €100 million mixed-use lifestyle development in Gzira, which has been given the green light.

The project will feature three high-rise buildings of 13, 27 and 33 floors over a public piazza connecting  Enrico Mizzi and Testaferrata streets.

Dr Muscat said the project would employ around 400 locals and its wealth would trickle down to residents by increasing the value of their property.