The ministers have been accused of criminalising the flying of the European Union flag on government buildings in England, as London's City Hall was told it could be prosecuted for displaying it on the anniversary of the Brexit referendum.
Seven years after the referendum on Brexit, London authority GLA had planned to fly the flag on Friday, but officials were advised that under the latest regulations they would need to secure permission from the local authority.
Without so-called advertising consent from Newham Council, City Hall, which is the headquarters of the GLA and is where Sadiq Khan, the capital's mayor, is based, would have been liable to criminal prosecution under the modified town and country planning control of advertisements regulations.
There is no such consent required to fly the flag of any country in England.
Also exempt are the flags representing the Commonwealth, the United Nations, sports clubs, the NHS, defined award schemes such as eco-schools and the rainbow flag, of six horizontal equal stripes of red, orange, yellow, green, blue and violet.
The EU flag was also among those that did not require permission until 2021, but the law applying to England was changed on 31 January 2020 as a response to the UK's departure from the EU.
Ministers at the time pressed the government to fly the union flag of the UK throughout the year on national government and local authority buildings.
Khan will instead of using lights to display the EU flag's blue and yellow colours on the building to mark the anniversary of the Brexit vote.
The mayor is proud to fly flags from City Hall, from the Union flag to the Ukrainian flag, a city hall source said. Creating a flag is a way of showing respect, embracing our values, and showing pride in our shared identity.
With over a million people calling London their home from other European nations, it s remarkable that the government has effectively banned the European flag from being flown without going through a long and bureaucratic planning process.
We were able to show our gratitude with a small gesture for a single day of the year by showing our gratitude to Europeans, who contribute significantly to our social and economic life. On a 69.7 percent turnout, 59.9% of Londoners voted to stay in the EU on June 23 compared with 40.1% who voted to leave the EU.
In London, seven of the 10 areas with the highest percentage of votes for remain were Hackney, Lambeth and Haringey, where more than 75% were to stay in the bloc.
In an open letter to Londoners from one of the 27 EU member states to mark the anniversary of the referendum, Khan wrote: Seven years ago our country voted to leave the European Union. It was a heartbreaking day for me, and I know it was for many of you too.
In the years since Brexit, there has been a lot of damage to our city and created a lot of uncertainty for many of you. Despite the appalling uncertainty over settled status, despite being used as bargaining chips in the negotiations, and despite the anti-migrant rhetoric coming from this government, you kept the faith and persevered to make London your home. Khan argued that he would back Keir Starmer's call for EU citizens who live and pay tax in the UK to have the right to vote in general elections. The prospect of enfranchising about 5 million EU citizens over the age of 18, living in the UK, could be a significant boost to the EU's economy.
The Department of Levelling Up, Housing and Communities declined to comment.