Controversial right-wing Dutch MP Geert Wilders will travel to the UK today after Home Secretary Alan Johnson said he was "not minded" to refuse him entry.
Mr Wilders, who won an appeal on Tuesday against a decision to turn him away in February, is due to arrive at Heathrow airport.
He is expected to be ushered away from the flight amid tight security before holding a press conference in London later.
But Mr Wilders, 46, is not due to show his short film Fitna, which criticises the Koran as a "fascist book".
The Home Office said it "stood by" its earlier decision and warned Mr Wilders his "statements and behaviour" could lead to him being turned away in future.
But a spokesman said Mr Johnson was "not minded" to recommend refusal "on this occasion".
The February decision was based on the fear that Mr Wilders' presence could have led to "inter-faith violence", the spokesman added.
He said: "We are disappointed by the court's decision. The Government opposes extremism in all its forms.
"Any European visitor's right to enter the UK will be considered on its merits by an immigration officer.
"On this occasion the Home Secretary is not minded to recommend that Wilders is denied admission to the UK.
"Clearly Mr Wilders' statements and behaviour during a visit will inevitably impact on any future decisions to admit him.
"The decision to refuse Wilders admission in February was taken on the basis that his presence could have inflamed tensions between our communities and have led to inter-faith violence.
"We still maintain the view that this was the right decision at the time and are minded to appeal against the court's decision and will take a final view once the court's written judgment is made available next week."
The Asylum and Immigration Tribunal overturned the ruling against the head of the Freedom Party, saying there was no evidence to suggest he represented a real and serious threat to a "fundamental interest" of society.
Even if there had been evidence, it would have been wrong to turn him away, the judges concluded.
Under those circumstances, they said, the police would have been able to ensure order and remove him if there was any trouble.
"It was more important to allow free speech than to take restrictive action speculatively," they said.
Mr Wilders said on Wednesday: "I am really very pleased that the UK court overturned the decision of the UK Government.
"It's not only a victory for me, it is a victory for freedom of speech.
"If you really adhere to freedom of speech, also people you disagree with you, give room for them to speak out."