The Labour London mayor said the EU was crucial to the city’s economic success.
He said: “Leeds is now one of the financial capitals of Europe. One of the reasons is because you’ve got companies from around the world coming to our country to have their European headquarters here.
“The services sector in Leeds is massive and I worry about people not realising the importance of the EU to Leeds booming.
“I think there’s a positive patriotic case to remain in the EU. It protects our jobs, protects wages, protects workers’ right but actually I worry about the consequences should we leave.”
Mr Khan claimed the mayor of Paris had already told him the city was ready to welcome companies that would desert the UK in the event of it leaving the EU and he argued Yorkshire has a lot to lose.
The London mayor was in Leeds today where he spoke to supporters gathered outside Leeds Town Hall as part of a wider tour of the region to rally backing for remaining in the European Union.
The Remain campaign hope senior Labour figures such as Mr Khan can persuade his party’s supporters to vote to keep Britain in the European Union in next Thursday’s referendum.
Immigration is thought to be one of the major issues fuelling support for Leave in areas that have traditionally backed Labour in Yorkshire.
Mr Khan called for politicians to take responsibility for the pressures on public services in some areas as a result of immigration rather than using them as a way to persuade people to vote Leave.
He told Yorkshire Evening Post: “The starting point is immigration has brought huge economic, cultural and social benefits to our country and we must always recognise that.
“The reality is though we have to recognise there are many, many people who have got problems getting decent housing, they’ve got problems in terms of waiting times to see a specialist in the NHS, they’ve got problems in relation to getting their children in a local school.
“Now the reality is we politicians must accept the responsibility and the blame for that and make sure we build the genuinely affordable homes, we’ve got to invest in the NHS, we’ve got to make sure schools are big enough to take the children.
“I’m not sure blaming immigration solves the problem. Rather than playing on people’s fears we’ve got to address them.”