London, England - Protests have erupted in London, with Saudi Crown Prince Mohammad bin Salman beginning his visit to the UK with a meeting with Theresa May, British prime minister.

Hundreds of demonstrators stood on Downing Street, holding signs with "Hands off Yemen" and "No more profits from bin Salman's wars" outside May's office.

According to Downing Street, the meeting between the 32-year-old Mohammad bin Salman, better known as MBS, and May will tackle international challenges, such as terrorism, extremism, the conflict and humanitarian crisis in Yemen and other regional issues such as Iraq and Syria.

Saudi Arabia is currently heading a US-backed military coalition fighting Houthi rebels in Yemen.

Saudi Arabia and the United Arab Emirates (UAE) have maintained a blockade on food and much needed medicine in the Houthi-controlled regions of Yemen, resulting in a cholera outbreak and widespread hunger.

Robin McGhee, 26, told Al Jazeera he came to the protest because "British government support for Saudi [Arabia] is an exceptionally bad act in the history of British foreign policy and I'm frankly just embarrassed that my country is doing something as unethical as actively helping the Saudi government in its devastating war in Yemen".

'Grotesque' foreign policy

Garry, a 35-year-old teacher who declined to give his last name, agreed. He thought MBS's visit was an "absolutely grotesque crystallisation of what is wrong with British foreign policy ... we are selling arms to Saudi when it is bombing Yemen, causing death, starvation and famine on a catastrophic scale".

Labour MP Chris Williamson, who was in attendance at the protest, echoed the feelings of protesters during a speech.

Williamson told the crowd he was "[a]bsolutely appalled with the humanitarian disaster that is being perpetrated in Yemen by the Saudi regime and it is being made possible by the armament of this country".

Labour Party leader Jeremy Corbyn said during a fiery debate with May that British military advisers based in Saudia Arabia were "directing the war" in Yemen and that the UK government was colluding in what could be war crimes.

The UK government made over £1.1bn ($1.5bn) from arms sales to Saudi Arabia in 2017 alone, according to government figures.

The number caused widespread outrage and calls for May to end sales to Saudi Arabia.

However, the Conservatives, as well as the royal family, with whom MBS is scheduled to meet, are giving MBS the "red carpet equivalent of a state visit," Vince Cable, leader of the Liberal Democrat Party, said.

In a newspaper opinion piece on February 28, Boris Johnson, British foreign secretary, praised MBS's Vision 2030 national programme, said to be aimed at modernising the Arab Gulf state, adding that he deserved Britain's support.

The Financial Times newspaper reported on Monday that Saudi Arabia and the UK will sign a series of agreements during the visit, in deals that diplomats said could be worth more than $100bn.

"The UK government recognises Saudi Arabia is very profitable for British arms exports and so the issue of human rights in the kingdom is not to the fore in current government thinking, in the sense of money talk," Paul Rogers, professor at Bedford University's Peace Department, told Al Jazeera.

Seems to be a number of propaganda trucks driving around London as well to help us 'welcome' him pic.twitter.com/aqfsBcCKVk — Jack Stewart (@jjstewart457) March 6, 2018

Leading up to the visit, there had been visible efforts in London to both welcome and reject the crown prince.

While demonstrators have driven vans through London's streets with posters saying "The UK should not welcome war criminal Mohammad Bin Salman", social media users posted images online of other vehicles carrying messages such as: "#Welcome Saudi Crown Prince".

MBS is also credited with leading a series of social reforms, such as allowing women to drive and lifting a 35-year ban on cinemas.

However, activists have warned against interpreting these reforms as heralding new freedoms.

They contend Saudi Arabia still has a poor human rights record both domestically - the kingdom carried out over 100 executions in 2017 alone - and internationally.

Since the Saudi-led military intervention started in Yemen in March 2015, the Arab world's poorest country has found itself on the brink of a devastating humanitarian crisis, with at least 10,000 people killed.

British arms companies are some of the biggest suppliers of weapons to Saudi Arabia, and the British government has approved billions of pounds in export licences over the past three years.

Campaigners accuse MBS of being the "chief architect" of the Yemen war, which has led to what the UN describes as the world's worst humanitarian crisis.

According to Campaign Against Arms Trade (CAAT), one of the groups leading Wednesday's protests, the UK has licensed £4.6bn ($6.4bn) worth of arms to Saudi Arabia in the past three years, including 2017.

The pictures of the crown prince on the steps of Downing Street will be projected around the world, and will be used by the regime to legitimise it on the world stage. Theresa May is handing a major propaganda coup to the dictatorship. Andrew Smith, Campaign Against Arms Trade

"The crown prince has overseen the brutal repression and abuse of Saudi people, as well as terrible atrocities that have been carried out against the people of Yemen," Andrew Smith, head of CAAT, told Al Jazeera.

He accused Britain of failing to hold the Saudi government to account.

Smith called on May to halt all arms sales, saying: "For decades now, the UK has prioritised the interests of arms companies over those of Saudi people. For the last three years, it has prioritised them over the lives of Yemeni people, too."

Tens of thousands of Britons signed online petitions that called on May to cancel the trip and demanded Saudi Arabia halt executions.

Sophie Turner, a 24-year-old protester on Downing Street, told Al Jazeera that "short-term arms sales profit should not be valued above human rights and we should not be giving more practical and PR support to the Saudi regime after we've already licensed nearly 5bn worth of arms since the Yemen war began."

"This has to stop," Turner told Al Jazeera.