William Ruto, who became Kenya’s president two years ago riding on the crest of the Christian vote, has been visibly shaken to find that over the last few months church leaders of all creeds are losing faith in him - seeing him less as a saviour and more as the greedy biblical tax collector.

In the run-up to his victory, some of his most ardent evangelical supporters had dubbed him "David", after the shepherd boy in the Bible who rose to become king.

The opposition had baptised him "deputy Jesus", accusing him of using Christianity to gain political capital as he attended church services from Catholic masses to the gatherings of obscure sects.

He would wear the appropriate religious attire for each setting, sometimes knelt in supplication and on occasion was moved to tears by sermons.

Afterwards, he credited God for his electoral success, and continued this practice of criss-crossing the country to attend a different church each Sunday.

But following massive opposition to the tax hikes imposed by his government, the 57-year-old gained a new nickname: "Zakayo" - which is Swahili for Zacchaeus, the wealthy and unpopular Jericho tax collector featured in the Bible.

The president has always maintained that if people want better public services and a reduction in the country’s debt burden, they have to pay up.

Over the last two years, taxes on salaries have gone up, the sales tax on fuel has doubled and people are also paying a new housing levy and a health insurance tax that is yet to benefit many Kenyans.

When momentous anti-tax protests erupted in June, the young people who led them, popularly referred to as Gen Zs, also called out churches for being too close to politicians and allowing them to preach from their pulpits.

Their anger forced the government to retract a controversial finance bill that had included more tax increases - and it woke up the churches, whose clergy began to openly criticise Ruto and his policies.

This too was a momentous development as the faith economy is big business in a country where more than 80% of the population are Christian - and a fundraiser with the right politician can greatly improve the fortunes of a church.

Last month, Teresia Wairimu, founder of Faith Evangelistic Ministries (Fem), a church in the capital, Nairobi, where Ruto and his family have frequently worshipped, suggested their King David was heading back to the field where sheep grazed.

"As a voter, I’m embarrassed," she said in her sermon.

Another sermon by Rev Tony Kiama of the River of God Church recently went viral after he called out Ruto’s government for "not serving God’s purpose but an evil one", citing the killings during the recent protests, the rising cost of living and every-day corruption.

The most hard-hitting criticism was last week’s statement from Catholic bishops, who carry more weight because of the respect and influence they command in Kenya.

They accused Ruto’s government of perpetuating a "culture of lies", citing unfulfilled campaign promises.

"Basically, it seems that truth does not exist, and if it does, it is only what the government says," the Kenya Conference of Catholic Bishops said, also hitting out at corruption, greed and over-taxation that was stifling the economy.

One bishop dubbed Kenya an "Orwellian dystopian authoritarian" state, where dissent was met “with intimidation, abduction or even assassination".

This was a pointed reference to the 60 people who died and the 1,300 others arrested during the anti-tax demonstrations. A further 74 people have been abducted and 26 reported missing in the last five months, according to the state-run Kenya National Commission on Human Rights.

The stinging statement by the bishops was followed by the Church’s rejection of a $40,000 (£32,000) donation make by Ruto when he attended the Soweto Catholic Church in Nairobi last Sunday - with the Archbishop of Nairobi citing "ethical concerns and the need to safeguard the Church from being used for political purposes".

Many of Kenya’s Christians are Catholic - about 10 million people, or 20% of the population, according to government statistics.

Other Christians belong to a variety of evangelical churches and other denominations, including the Anglican Church of Kenya and the Presbyterian Church.

And the Catholic Church’s influence in Kenya goes beyond its congregation owing to its wide investment in education, healthcare and other social programmes.

It has also been angered by the chaotic transition to a new social health insurance scheme, with the government owing millions of dollars to faith-based hospitals.

The bishops’ outspoken assessment of the state of the nation has reminded Kenyans of the role church leaders played when they pushed for a return to multi-party democracy in the 1990s.

Brave clerics such as Ndingi Mwana a’Nzeki of the Catholic Church, Alexander Muge, Henry Okullu and David Gitari of the Anglican Church and Timothy Njoya of the Presbyterian Church fearlessly challenged the repressive and single-party rule of then-President Daniel arap Moi.

But analysts say under Moi’s successors - Mwai Kibaki and Uhuru Kenyatta, both Catholics - clerics lost their voice.

"Under President William Ruto, things got even worse because important elements of the church were seemingly co-opted into the feeding trough," veteran journalist and columnist Macharia Gaitho wrote in Kenya's Daily Nation newspaper this week, suggesting "churches were bribed into silence".

The Catholic bishops’ stance has won support from other denominations, as well as Muslim clerics - despite the widespread faith-based support Ruto enjoyed previously for his tough stand on gay rights and his conservative views on abortion.

A joint statement by some Pentecostal and evangelical leaders hailed the bishops for their bravery and also for "doing the unthinkable" in rejecting Ruto’s money.

Head of the Anglican Church of Kenya Archbishop Jackson Ole Sapit, who led national prayers on the day Ruto was declared winner of the presidential race, joined Catholic bishops in condemning what he described as "escalating misrule, impunity, and widespread rights violations".

"In the circumstances, we should not simply fold our hands and pray for miracles," Ole Sapit said, adding that the Catholic bishops reflected the feelings of many Kenyans.

Baptist cleric Daniel Wambua added that religious leaders were now determined to end the "transactional relationship" with the state.

Meanwhile Sheikh Abubakar Bini, chair of the North Rift Council of Imams and Preachers of Islam, urged the government to take the bishops' remarks as advice rather than criticism.

At first, Ruto and his allies hit back - one accusing the bishops of spreading "misinformation".

But analysts say Ruto, who frequently uses the scriptures to respond to critics, should be wary of a direct confrontation with the churches as even smaller ones can have thousands of followers who could negatively affect his re-election bid.

The president is already facing rebellion in parts of his 2022 political strongholds after the impeachment of former Deputy President Rigathi Gachagua last month.

They fell out over the handling of the anti-tax demonstrations, which have rocked Ruto’s administration to its core.

A close ally of the president, MP Oscar Sudi, has taken to X to eat some humble pie, apologising to Catholic bishops on behalf of the government.

Ruto himself has since appeared to soften his response to the growing criticism, saying he has heard the clerics and is ready to engage further.

"We have made undeniable progress in our country. However, there remains much to be done. We must continue working together to hasten the delivery of our commitments and change Kenya," he tweeted on Thursday.

What Kenya’s first evangelical Christian president is having to accept is that the churches he used so successfully to take state house could well help unseat him in the next election.

"He knows he cannot fight the church," said Mr Gaitho.