Kenyan senators have voted to remove Deputy President Rigathi Gachagua from office despite his failure to testify at his impeachment trial after his lawyer said he had been taken to hospital.

In one of the most dramatic days in Kenya's recent political history, Gachagua had been due to appear in the Senate to defend himself on Thursday, a day after he had pleaded not guilty to 11 charges.

However, Gachagua, popularly known as Riggy G, did not show up and his lawyer requested a postponement saying his client was suffering from chest pains and was being treated by doctors at The Karen Hospital.

Senators chose to continue the trial without him, prompting the defence team to leave the chamber.

The senators’ refusal to delay proceedings until Saturday - as long as would have been legally allowed - shows their determination to oust Gachagua, several months after he fell out with President William Ruto.

Last week, an overwhelming majority of MPs in the National Assembly - the lower house of parliament - voted to impeach him, setting the stage for his two-day trial in the Senate.

Gachagua, a wealthy businessman from the vote-rich central Mount Kenya region who was present in the house on Thursday morning before falling ill, has described the impeachment as a "political lynching".

President Ruto has moved quickly to name a replacement and on Friday morning, nominated Interior Minister Kithure Kindiki to become his deputy. This has been unanimously approved by parliament.

The 52-year-old is a close ally of the president and served as his lawyer during his trial for crimes against humanity at the International Criminal Court (ICC) that was eventually dismissed because of a lack of evidence.

However, in another dramatic development on Friday, the Nairobi High Court has suspended the impeachment, and Kindiki's swearing-in.

On Thursday evening, the required two-thirds of the 67 senators upheld five charges including inciting ethnic divisions and violating his oath of office.

This is enough for him to to be removed from office.

The unprecedented move means he cannot hold public office again and he also loses any retirement benefits.

He was cleared of six charges including corruption and money-laundering.

This comes just two years after Ruto and Gachagua were elected on a joint ticket.

The vote draws a line under months of infighting at the top level of government and consolidates Ruto’s hold on power.

The row came to a head in June when Gachagua, in an act seen as undermining the president, blamed the head of the intelligence agency for not properly briefing Ruto and the government over the magnitude of mass protests against unpopular tax hikes.

In a huge blow to his authority, Ruto had just been forced to withdraw the taxes. He sacked his cabinet and brought in members of the opposition to his government.

At the start of the trial, one of Gachagua’s lawyers, Elisha Ongoya, said all of the allegations were "either false, ridiculous or embarrassing".

Before the vote, Gachagua had said he would challenge the decision if it passed.

A doctor is quoted by the Reuters news agency as saying the 59-year-old had gone to hospital with heart trouble, but was stable and undergoing tests.

Ruto has not commented on the impeachment of his deputy or his removal from office besides informing parliament on Friday of his nomination of Kindiki.

Ruto and Gachagua were elected on a joint ticket two years ago - and the partnership helped Ruto win by marshalling support in Mount Kenya, the heartland of the Kikuyu people who are the largest voting bloc in Kenya.

Ruto himself became deputy president on a joint ticket with Uhuru Kenyatta, also a Kikuyu - but fell out with his boss who refused to back him to become president in 2022.

The pair had joined forces when they both faced trial at the ICC for their part in electoral violence following the 2007 election in which 1,200 people were killed.

The prosecution dropped charges against then-President Kenyatta in 2014 and judges threw out the case against Ruto in 2016, one noting a "troubling incidence of witness interference and intolerable political meddling".

Kindiki, who also from the Mount Kenya region, had been a top contender to replace Gachagua.

His nomination requires parliamentary approval before he is sworn in, but it is unlikely to face difficulties as Ruto has the majority in parliament as well as the backing of the main opposition party.