From left to right: European Union High Representative Federica Mogherini, Iranian Foreign Minister Mohammad Javad Zarif, Head of the Iranian Atomic Energy Organization Ali Akbar Salehi, Russian Foreign Minister Sergey Lavrov, British Foreign Secretary Philip Hammond and US Secretary of State John Kerry pose for a group picture at the United Nations building in Vienna, Austria, Tuesday, July 14, 2015. After 18 days of intense and often fractious negotiation, diplomats Tuesday declared that world powers and Iran had struck a landmark deal to curb Iran's nuclear program in exchange for billions of dollars in relief from international sanctions, an agreement designed to avert the threat of a nuclear-armed Iran and another U.S. military intervention in the Muslim world. (Joe Klamar/Pool Photo via AP)

From left to right: European Union High Representative Federica Mogherini, Iranian Foreign Minister Mohammad Javad Zarif, Head of the Iranian Atomic Energy Organization Ali Akbar Salehi, Russian Foreign Minister Sergey Lavrov, British Foreign Secretary Philip Hammond and US Secretary of State John Kerry pose for a group picture at the United Nations building in Vienna, Austria,, July 14, 2015.. (Joe Klamar/Pool Photo via AP)

Philip Hammond has been urged by a former cabinet colleague to press Iran on its support for terror groups during his visit to Tehran to reopen the British Embassy this weekend.

In the latest sign of a thawing of long-strained relations, it was announced yesterday that the embassy will start operated four years after being stormed by protesters over sanctions from the international community. The Iranian embassy in London is also expected to reopen.

It comes a month after world leaders including Britain and Iran signed an agreement – heavily criticised by Israel – to curb its nuclear programme in return for sanctions relief.

Conservative Friends of Israel Parliamentary Chairman Eric Pickles MP said difficult questions must be posed.

“The Foreign Secretary must make strong representations to Iran that its well-documented support for international terror groups is wholly unacceptable,” he said. “Just this week, Iran’s Supreme Leader Ayatollah Khamenei vowed that the country will “take all possible means to support anyone who fights Israel”. Iran’s ongoing attempts to destabilise the region warrants unequivocal condemnation.”

He added: “Iran’s human rights record is equally lamentable. The Foreign Secretary should express the United Kingdom’s horror at Iran’s surge in the use of the death penalty and suppression of even the most basic of human rights.”

These issues were not part of negotiations on the nuclear agreement.

Israel has claimed the nuclear deal helps pave Iran’s route to the bomb – a claim strongly denied by the US and other negotiators.