Kenya's election 2022: Rigathi Gachagua and Martha Karua chosen as running mates

Both main candidates for the deputy presidency, Martha Karua (L) and Rigathi Gachagua (R), are from the Kikuyu ethnic group

The two leading candidates in Kenya's presidential election have chosen running mates from the vote-rich Kikuyu ethnic group to bolster their chances of winning August's much-anticipated poll.

Deputy President William Ruto has picked businessman Rigathi Gachagua while former Prime Minister Raila Odinga has settled for former Justice Minister Martha Karua.

"The two are worlds apart, save for the fact that they come from the Mount Kenya region," analyst Javas Bigambo told the BBC.

The Mount Kenya region is home to the Kikuyu community, the support of which could be vital to determining the outcome of the election.

Mr Gachagua is a strong mobiliser and has the ear of struggling Kikuyus, who have been backing Mr Ruto over his plans to address economic grievances.

Ms Karua is a political icon beyond the Kikuyu - and is known for her passion for judicial reform and campaigns against corruption.

Analysts say that while the intellectual elite might go for the avid anti-corruption campaigner, this election is mostly about economic reforms.

"Both sides are tainted by corruption allegations and that is why none is pointing fingers. Corruption is no longer an issue. It seems to be our way of life and it has become hard to show a strong leader who is not tainted by corruption," analyst Bobby Mkangi told the BBC.

Mr Gachagua is facing charges of corruption and money-laundering worth $65m (£53m). He denies the charges, and says he is being persecuted by the state for supporting Mr Ruto.

Businessman Rigathi Gachagua (L) is running on William Ruto's ticket (R)

Outgoing President Uhuru Kenyatta is supporting Mr Odinga, with whom he famously shook hands in 2018 to signal that they had reconciled after years of political acrimony.

Analysts say that since then, Mr Odinga, a veteran opposition leader who has failed in four previous attempts to win the presidency, has largely ignored all the rot in government.

His choice of Ms Karua as running mate is also an attempt to win the female vote, but Mr Bigambo is not sure how successful she will be.

"She appeals to the women academically and not practically. She only appeals to part of the middle class and the NGO community who do not have a strong bearing on the election outcome," Mr Bigambo says.

Raila Odinga (R) has chosen the high-profile Martha Karua (L) as his running mate

Ms Karua ran to be president in 2013 and got 43,881 votes - or 0.36% of the total number cast.

But she is known for being bold and an astute fighter for multi-party democracy.

She has walked out on two former presidents.

In 2001 she stormed out of an event attended by then-President Daniel arap Moi, protesting against comments made against her then-party leader Mwai Kibaki.

Ms Karua resigned as justice minister in 2009 citing frustrations after Mr Kibaki, the president at the time, appointed judges without her knowledge.

"The big question is whether or not she has the capacity to step out as the Mount Kenya supremo now that President Uhuru is retiring. Will she be fully embraced among the lower ranks of Mount Kenya?" Mr Bigambo asks.

Uhuru Kenyatta is stepping down after two terms in office

Mr Gachagua on the other hand has been lauded by analysts for his ability to tap into the political network he was part of while working as President Kenyatta's personal assistant and as a district officer in different regions.

"His ability to negotiate his way to this position considering other names that were fronted and were known nationally is quite something," Mr Mkangi says.

Mr Gachagua is the member of parliament for Mathira constituency in central Kenya, which has produced three of Kenya's four presidents - Jomo Kenyatta, Mwai Kibaki and Uhuru Kenyatta.

He is a businessman whose speeches on the campaign trail suggest he understands the issues affecting the Kikuyu.

"He is the feared political bulldog that Ruto needed to be able to counter President Uhuru in the central region," Mr Bigambo says.

Despite economic issues emerging in this election as a possible determinant in how people will vote, ethnicity still has a strong influence on the electorate.

This is the first time since Kenya's independence that a Kikuyu has not emerged as the main presidential candidate - Mr Ruto is a Kalenjin, the third biggest ethnic group, and Mr Odinga is a Luo, the fourth biggest ethnic group.

The two have therefore both nominated a Kikuyu - the largest ethnic group - as running mates for the 9 August election, a decision that could make or break their presidential campaigns.

"The choice of the running mates from the Kikuyu community was the only way the bloc was going to be incentivised to come out and vote," Mr Mkangi says.