Ofcom has cleared al-Jazeera of antisemitism and breaching impartiality rules over an undercover investigation that caught an Israeli embassy official plotting to “take down” British MPs regarded as hostile towards Israel.

The media regulator investigated the Qatar-based broadcaster after receiving complaints about The Lobby, a four-part documentary investigating the political influence of the Israeli embassy in Britain.

Clayton Swisher, the director of investigative journalism at al-Jazeera, said in a memo to staff that Ofcom had “fully and completely vindicated” the broadcaster.

The ruling comes as al-Jazeera battles for its future. A coalition of Gulf states, including Saudi Arabia, the United Arab Emirates and Egypt, have demanded that Qatar close the TV station as one of the conditions of lifting a blockade of the gas-rich kingdom. Israel also wants to close al-Jazeera’s offices, with the prime minister, Benjamin Netanyahu, accusing it of inciting violence.

Al-Jazeera aired The Lobby in January. The programme showed Shai Masot, an official in the Israeli embassy in London, saying he would “take down” MPs including Sir Alan Duncan, the Foreign Office minister who is an outspoken supporter of a Palestinian state.

The Israeli ambassador subsequently apologised for the comments and Masot resigned.

Ofcom cleared al-Jazeera after concluding it did not make allegations in the documentary that were based on the grounds of individuals being Jewish and that it had included the view of the Israeli government in the programme. It ruled that al-Jazeera had not breached rule 2.3, which relates to offensive matter, and rule 5.5 with regards to impartiality.

The regulator said in its ruling: “It was the view of some complainants that The Lobby fuelled harmful stereotypes about Jewish people controlling or seeking to control powerful organisations. These complainants considered this was antisemitic and offensive.

“We considered that the allegations in the programme were not made on the grounds that any of the particular individuals concerned were Jewish and noted that no claims were made relating to their faith. We did not consider that the programme portrayed any negative stereotypes of Jewish people as controlling or seeking to control the media or governments. Rather, it was our view that these individuals featured in the programme in the context of its investigation into the alleged activities of a foreign state – the state of Israel acting through its UK embassy – and their association with it.”

Ofcom added: “Complainants considered that the programme only took a one-sided view on this matter. However, we considered that the viewpoint of the Israeli government was included in the programme in a number of linked ways.”

An al-Jazeera source welcomed the ruling, saying: “This goes to show that no matter what al-Jazeera’s critics say, its journalism meets and exceeds the highest standards of objectivity and balance. We feel vindicated by the rulings and ever more committed to exposing human rights violations by anyone – regardless of geography, religion, or the power of their lobbies.”