Officers say that they have not told John Richards he is committing an offence for displaying the poster but said he could only face arrest if he causes offence and refuses to take the poster down when they ask.

In a statement Lincolnshire Police said the 1986 Public Order Act states that a person is guilty of an offence if they display a sign which is threatening or abusive or insulting with the intent to provoke violence or which may cause another person harassment, alarm or distress.

The statement adds: “This is balanced with a right to free speech and the key point is that the offence is committed if it is deemed that a reasonable person would find the content insulting.

“If a complaint is received by the police in relation to a sign displayed in a person’s window, an officer would attend and make a reasoned judgement about whether an offence had been committed under the Act.

“In the majority of cases where it was considered that an offence had been committed, the action taken by the officer would be to issue words of advice and request that the sign be removed.