Amani National Congress Party leader, Musalia Mudavadi says he has taken the role of keeping the government in check.
The ANC leader said he assumed the role since Nasa coalition, in which he was a co-principal, now exists only on paper as a legal entity.
He said that the political parties forming the coalition ceased to operate as a single unit.
In an interview where he restated his wish to provide an alternate approach to addressing issues that affect Kenyans, Mr Mudavadi said he would stand firm as the face of opposition.
"I have been the most vocal [opposition leader] when it comes to raising concerns on issues affecting the country. I believe I'm filling the opposition gap to ensure that Kenyans have an alternative voice," Mr Mudavadi said on Tuesday.
He called for sanity in the way the opposition operates.
"Kenyans should move away from the notion that opposition should be disruptive, we need to start returning sanity and integrity to the country's politics," said Mr Mudavadi.
The ANC leader acknowledged that despite being part of the abrasive opposition in 2017, there was need to look at the opposition afresh.
The ANC leader distanced his style of leadership from that of the Raila Odinga-led Orange Democratic Movement.
He said that while the ODM leader had fashioned himself in the manner that he is often perceived, he (Mudavadi) should be looked at differently.
Mr Mudavadi, however, denied being part of the group that seeks to protect status quo and political dynasties.
"My grandfather worked as a simple gold miner, using the most simplistic tools. He left my father, who struggled to take care of his siblings in poverty, aged only nine," said the ANC leader who maintained that he had a humble upbringing.
He, however, ruled out the possibility of vying as Deputy President William Ruto's running mate, in the 2022 elections.
"[Dr] Ruto cannot be anyone's running mate. He will be contesting as a president just like I will be. So it is best to start uniting ANC, which is what I am doing," he said.
On issues affecting his party, he said that no one was targeting Kakamega Senator, Cleophas Malala and nominated MP Godfrey Osotsi.
He, however, said that there is need for accountability.
"I don't mind what their political persuasions are in these matters. But party's accountability must be respected. I'm not targeting anyone, what wrong has Hon Malala done so that I target him," he asked.
He however welcomed the latest move by former Sports Cabinet Secretary, Rashid Echesa to work with him. He said that Mr Echesa had expressed his wish to have a united people from Western Kenya.
About former Kakamega Senator Bonny Khalwale working with Jubilee Party he said: "Dr Khalwale had found a new calling and is best left to attend to his new calling. "I cannot help him."