Cape Town's newly-elected Mayor Dan Plato has threatened to take legal action against the national government if the City does not get more police officers.

"If the national government does not urgently address this, we will take the legal route to force them to give us more police," said Plato.

"We are done asking nicely," said the former community safety MEC. Plato has replaced Patricia De Lille, who resigned last week.

Plato was elected mayor on Tuesday after 146 councillors out of 208 voted in his favour via a secret ballot.

With the mayoral chain finally resting on his chest, Plato also promised extra metro police officers and vowed to make sure the recently returned anti-gang unit, launched on Friday, was here to stay.

He called on councillors to unite to provide integrated services that would break down old apartheid-era planning, to work towards better housing closer to the city, and for the repair of Metrorail's crippled transport system.

"I will not be able to do it alone and will need the support of everyone who serves this city's vision," said Plato.

The other nominees for mayor on Tuesday were Xolani Sotashe from the African National Congress (ANC), and the African Christian Democratic Party's Grant Haskins, who received 53 and 3 votes respectively. Six ballots were spoilt.

It is Plato's second time as mayor, having previously served before De Lille's term began in 2011. He succeeds her this time, after she resigned last Wednesday.

Among those present to watch his election included Bonginkosi Madikizela, Democratic Alliance (DA) leader for the Western Cape.

However, Sotashe, the leader of the ANC opposition in council, blamed Plato for an increase in crime in some parts of the city.

"Too many communities in the province have not had the luxury of feeling safe in their communities," said Sotashe.

Plato received messages of congratulations from many party representatives during an allotted time for comment after his election, but some councillors used their time for criticism.

Haskin said the DA, whose ticket Plato was elected on, always blamed national government for any problems the council experienced.

As Plato was settling in, a large group of striking MyCiTi bus drivers sat on the steps of the Civic Centre.

They want the City to hire them directly, instead of being hired by vehicle operating companies commissioned to run the buses.

They have been on strike since October 14 and, on Tuesday, a bus was set alight at the Omuramba station in Milnerton.