Democratic Party MP Marlene Farrugia warned Nationalist members that a victory for Adrian Delia in today's leadership contest would signal the death knell for the PN.

In a Facebook post, Dr Farrugia wrote: "If the members choose Delia, they will be destroying the Opposition and burying the PN. I said what I had to say."

Dr Delia is up against Chris Said at the climax of a tense contest to replace Simon Busuttil following the heavy electoral defeat in the June 3 election. 

The outgoing PD leader and MP, elected under the Forza Nazzjonali banner with the PN in the last election, said members had a choice to make. 

Marlene Farrugia's Facebook post.

If they wanted to unite and renew the party to render it a winner then they should clearly choose Dr Said. 

In a veiled attack on Dr Delia, she said members had a choice to go for a leader who would transform the PN into a weak copy of the Labour Party, thus enabling Joseph Muscat to "roll over everybody and keep winning elections".

Dr Delia is seen as a party outsider who has vowed to clear the "establishment" if elected. He is believed to have an edge over Dr Said in today's contest. 

The leadership contender and some prominent PN officials and MPs have openly been firing broadsides during the campaign. Only this morning, witnesses reported a tense argument between MP Jason Azzopardi and Dr Delia's brother.