A lawyer representing Kenya's Deputy President Rigathi Gachagua in his impeachment hearing told the Senate on Thursday that the politician was "very sick" and in hospital, after he failed to attend proceedings.

The National Assembly voted last week to impeach Gachagua, who helped President William Ruto win an election two years ago but has been assailed by allies of the president over alleged disloyalty and a series of provocative public comments.

Gachagua was due to defend himself against the 11 impeachment charges in the Senate on Thursday afternoon, before senators take a vote on whether to remove him from office.

"The sad reality is that the deputy president of the republic of Kenya has been taken sick, very sick, and as I address, Mr Speaker, this honourable house (of) Senators, he is in hospital," Gachagua's lawyer Paul Muite said.

Senate Speaker Amazon Kingi suspended the hearing and gave Gachagua until 17:00 to appear before the Senate. Gachagua has previously called the impeachment process a political lynching based on falsehoods.

Ruto, who has fallen out with Gachagua in recent months, has not commented on proceedings, but faces a public backlash if his deputy is ousted, political analysts said.

Many Kenyans view the impeachment process as politically motivated, and a distraction from the aftermath of the deadly anti-tax protests in June and July which exposed deep discontent with government policies and alleged corruption.

The hearings, which have involved in-depth scrutiny of Gachagua's finances, could boomerang back at Ruto, said Karuti Kanyinga, a professor at the University of Nairobi's Institute for Development Studies.

"We are going to hear people demanding that the same thing that has been done on Gachagua be done to the president," Kanyinga said.

If two-thirds of senators back the motion in a vote scheduled for Thursday evening, Gachagua will become the first Kenyan president or deputy president forced from office by impeachment, a process introduced under the 2010 constitution.

Gachagua had been due to respond to a litany of accusations laid out on Wednesday by a lawmaker from Ruto's coalition.

The lawmaker, Mwengi Mutuse, said Gachagua had incited hatred in comments about ethnic minorities from his home region. Mutuse also accused Gachagua of acquiring properties worth over $40-million since becoming deputy president, despite reporting a net worth before entering office of only around $6 million.

In response, Gachagua's lawyer, Elisha Ongoya, said the allegations lacked evidence and were based on speculation.