David Cameron was forced to pause his long-awaited speech on immigration after he was drowned out by an alarm at the factory where he had chosen to make the announcement.
The Prime Minister joked that his immigration reforms had "set off alarm bells" in Brussels as the siren blasted for one minute and 29 seconds.
Mr Cameron initially ignored the noise and continued for more than half a minute before breaking off from the address at the JCB factory in Rocester, Staffordshire .
He said: "This has clearly set off alarm bells in the European Commission, which has a direct link back here to JCB, but I'm glad that it's had that effect."
The Prime Minister attempted to carry on with the speech before halting again, asking: "How are we getting on?"
He told the audience there would be a "brief pause" while the alarm was dealt with.
"I once made a speech in a car plant where actually they didn't stop the car plant operating and so I had to speak louder and louder as more and more cars came off the production line," he added.
"I thought it was a very healthy development because it showed how well our automotive industry is operating right now.
"I'm sorry to interrupt production at JCB. I know demand is high, I know your products are superb, I know they are required around the world and I promise as soon as I'm finished you can get the lines working again.
"But thank you very much and thank you for holding with me for that pause."