The Palestinian ambassador to the UK has said the inauguration of the state’s embassy in London is “proof that our identity cannot be denied”.

Husam Zomlot hailed the upgrading of Palestine’s mission in Hammersmith, west London, as “historic” and “monumental”.

Speaking at a ceremony marking its inauguration as an embassy, he said: “This is not merely a change of name, and the plaque we will unveil shortly represents far more than formality.

“It is a change of direction, reflecting the reality we are living today, a reality that unequivocally recognises, at long last, our inalienable right to sovereign statehood.

“For generations of Palestinians in Gaza, in the occupied West Bank, including East Jerusalem, in refugee camps and across the diaspora, this embassy represents proof that our identity cannot be denied, our presence cannot be erased, and our lives cannot be devalued.”

The upgrading of the embassy follows the UK government’s decision in September to recognise the state of Palestine in an effort to “protect the viability of a two-state solution” in the region. The building had before then served as the Palestinian mission to the UK.

The embassy’s flag-raising ceremony on 22 September was attended by MPs, ambassadors and a couple of hundred members of the public. Last month, Zomlot called for “comprehensive protection” of the embassy after it was targeted by masked men waving Israeli flags and union jacks. The building was defaced with stickers such as “I love the IDF [Israel Defense Forces]”, according to images captured by security cameras.

On Monday, Zomlot said Britain’s recognition of the Palestinian state was the result of “100 years of relentless struggle”, but added that he felt “the shadow that hangs over us today” as people in Gaza were “living in hell”.

Gaza’s health ministry says 422 Palestinians have been killed since the ceasefire took effect in October after two years of conflict. Most of the territory is in ruins, with its population of more than 2 million people living mainly in makeshift homes or damaged buildings in areas where Israeli forces withdrew.

Monday’s ceremony also heard from Obaidah, a 14-year-old Palestinian refugee wounded during the Israeli bombardment of Gaza last year and evacuated to the UK for medical treatment.

Saying he hoped one day to become a Palestinian ambassador, Obaidah added: “Having the embassy in the United Kingdom is very meaningful. It is a place where our people are seen, where our voices are heard, and where our hope for justice and dignity lives.”