Liberal Leader Matthew Guy remains steadfast he and others fully co-operated with the Victorian Electoral Commission in its probe into a donor scandal.

The VEC referred its investigation into Mr Guy and his former chief of staff Mitch Catlin to the Independent Broad-based Anti-Corruption Commission for further investigation on Thursday.

Mr Catlin resigned in August after it was revealed he asked a billionaire Liberal donor to make more than $100,000 in payments to his private marketing company.

Mr Guy has repeatedly said he and his party have fully co-operated with the electoral commission and denied exploiting a legal loophole to stymie the probe.

But the VEC has publicly contradicted that claim, declaring it has not received full co-operation from those involved.

“All the key players in that initial issue were invited to respond to questions,” VEC spokeswoman Sue Lang told Melbourne radio 3AW on Friday.

“We received no satisfactory response from anybody.”

In Werribee, Mr Guy maintained he had handed over all material requested through lawyers but revealed he had not had any direct contact with the VEC.

“I have totally complied to the full extent of the law and I will to anyone else that asks,” he told reporters.

“I’ve done nothing wrong. This is the first I’ve heard to the contrary.”

Asked if he was lying, Mr Guy said: “I don’t accept that whatsoever. That’s not the case.”

It comes as Mr Guy promised to overhaul the state’s upper house voting system after backroom preference dealings were exposed.

A covert video showing so-called “preference whisperer” Glenn Druery discussing manipulating the state’s upper house voting system was leaked by the Angry Victorians Party and published.

In the footage, Mr Druery explains his method to get candidates elected as part of Victoria’s group voting ticket system.

It allows parties to legally distribute upper-house preferences when people vote above the line.

Mr Guy challenged Premier Daniel Andrews to commit to reform after he declined on Thursday, wanting to wait for the verdict from parliament’s post-election committee.

A Labor-chaired committee in 2020 recommended an inquiry into group voting tickets following the 2018 election but it did not materialise.

Former state Labor deputy campaign director turned pollster Kos Samaras said it was a strategic error from the Andrews government not to act.

“The crossbench that they may be presented with may be full of anti-lockdown, anti-vax candidates,” he told AAP.

Meanwhile, the Premier proposed a $26 million package to add 40 Mobile Intensive Care Ambulance paramedics across the state – increasing the total number to 640 – if re-elected.

This includes a $10 million Australian-first Centre for Paramedicine in partnership with Victoria University, for advanced teaching and research.

“Those paramedics have the most advanced scope of practice,” Mr Andrews told reporters on Friday.

He also pledged to end outsourcing of Victoria’s patient transport sector by potentially having patient transport officers directly employed by Ambulance Victoria.

Asked about ambulance wait times, which have increased across Victoria since he first became Premier in 2014, Mr Andrews blamed the pandemic.

“We’ve had a one-in-100-year event, which I think all of us know only too well has put incredible pressure on our health system in a couple of ways – extra patients needing care but also enormous numbers of staff who simply couldn’t report for work,” he said.

– AAP