Downing Street has been forced to apologise after meat and alcohol were served at a No.10 reception to celebrate Diwali.

Keir Starmer took part in the event, which was held at the prime minister’s official residence last month.

A spokeswoman for the PM said there had been a “mistake” and insisted “it will not happen again”.

Shivani Raja, the Conservative MP for Leicester East, was among those who complained about the oversight.

Although Hinduism does not have a clear prohibition on alcohol or meat consumption, many of its followers choose not to drink and some are also vegetarian.

In a letter to the PM, Raja said: “I feel this speaks poorly against the organisation of this year’s event – with a disappointing lack of knowledge of the customs and traditions that many British citizens hold dear.

“As a practising Hindu, representing thousands of Hindus within my own constituency of Leicester East, I have been deeply saddened to hear that this year’s festivities were overshadowed in the greatest Office of State by negativity, as a result of this oversight.”

A Number 10 spokesperson said on Friday: “The prime minister was pleased to welcome a range of communities celebrating Diwali to a reception in Downing Street.

“He paid tribute to the huge contribution the British Hindu, Sikh and Jain communities make to our country and how the government is driven by the shared values of hard work, ambition and aspiration.

“A mistake was made in the organisation of the event. We understand the strength of feeling on this issue and so would apologise to the community and assure them it will not happen again.”