Multi-million dollar deals with various states in the Middle East have helped Tony Blair amass a fortune thought to be worth an estimated $90m, claims a book published this month.

Blair accepted the job of Middle East peace envoy with the Quartet (the United Nations, the US, the EU and Russia) on the same day as he stepped down from office in 2007.

The Quartet was established with the aim of finding a solution to the Israeli-Palestinian conflict, and as Special Envoy Blair has travelled extensively in the region, most recently to Gaza last month.

His trips to the region have also seen him strike lucrative deals with the region’s governments for consultancy work.

One of the biggest of these, revealed by the Sunday Times, was a proposed contract with the UAE worth up to $45m.

Tony Blair Associates, an umbrella organisation founded to coordinate the diplomat’s various consultancy groups, offered its services to the UAE’s Foreign Affairs Ministry in a five-year commercial partnership.

A 25-document about the September 2014 deal obtained by the Sunday Times states that “there is nowhere in the world right now where we could not work or provide the necessary contacts either politically or commercially, should we want to”.

Blair has worked in partnership with various governments whose human rights records have been criticised by international monitors. In 2013, he offered public relations advice to the president of Guinea after security forces shot protesters during anti-government clashes, killing nine people.

The contract with the UAE was proposed while Blair was working as Middle East peace envoy. He is now facing calls to step down from the position of envoy over allegations of a conflict of interest.

Andrew Bridgen, a Conservative MP who has called for former prime ministers to be bound by tighter regulations, accused Blair of “relentlessly cashing in his contacts” while the Middle East is “on fire".

“This is damaging to Britain’s reputation, and he should now stand down as the Middle East peace envoy."

Blair’s office responded to the allegations by saying that the document was “out of date” and insisting that he would never engage in paid work that caused a conflict of interest with his work as peace envoy.

“The UAE is not a member of the Quartet. Tony Blair has undertaken other paid work in the Gulf, but not in respect of anything that is linked to what he does unpaid for the Quartet.”

The UAE does not recognise the state of Israel, one of the parties in the Quartet’s peace efforts, and the countries have no official diplomatic or economic ties.

However, a recent investigation by Middle East Eye revealed that an Israeli-owned company has become responsible for a huge surveillance system that protects critical infrastructure in the Gulf kingdom.

Blair’s other work with Gulf States includes a $40m four-year contract for consultancy work with the Emir of Kuwait and a deal to provide the government of Abu Dhabi, the largest emirate in the UAE, with “global strategic advice” at a cost of up to $1.5m a year.

According to Blair Inc, a book by Francis Beckett and David Hencke, to be released this month, he also arranged a covert contract in 2010 with Saudi oil company PetroSaudi.

The deal, according to the book, saw Blair arrange introductions to contacts in China, and was reportedly worth $60,000 a month. He also supposedly earned 2 percent commission on any deal resulting from the introductions.

Blair has also said he is "happy to help" Egypt's President Abdel Fattah al-Sisi, though he denies working as a formal advisor to Sisi’s government, which launched a military takeover of the country in 2013.

An alleged leak that emerged last week claimed to feature Egyptian officials arranging for a visit by an Emirati delegation, who were "bringing along Tony Blair".

The purported leak, said to have been recorded in early 2014, appears to indicate that Blair and the Emirati officials spoke with high-level Egyptian politicians, including the president, the head of intelligence and the foreign minister, in "unofficial meetings".