The steel band booked to play Nigel Farage's carnival in Croydon refused to play after learning the show was for UKIP.
Dressed in their bright orange t-shirts Endurance Steel Orchestra got half way through a track when they decided to stop playing.
Speaking to UKIP candidate Winston McKenzie the band leader Marlon Hibbett said: "I did not know what we were coming here to do and if it had been made clear I would not have been here today.
"UKIP is not something that I agree with and I feel like I have been used."
But Mr McKenzie said "I said to you we are holding a political conference, can you play and you said 'no problem'."
Mr Farage was due to appear in Croydon at 2.30pm but has yet to appear.
It is understood his team is assessing the security risks.