The 61-year-old cleric told him to stop taking photographs of the van in front of the building, then ordered him to leave the cathedral close.
He now plans to tell the BNP, which hopes to put up candidates for county council elections in Staffordshire this year, not to publish any material featuring Lichfield Cathedral or imply that the Church of England supports its policies.
The party, which wants an end to immigration and the "voluntary resettlement" of foreign-born residents of Britain, believes it will receive a large number of votes because of opposition to a mosque being built in the city.
Earlier this year the Church of England's governing body, the General Synod, voted overwhelmingly to ban clergy and lay staff from being members of the group amid growing fears it is trying to disguise its extreme policies and portray itself as a Christian organisation.
The BNP is using a picture of Jesus in a new billboard campaign ahead of European elections in June, together with a quote from the Bible reading "If they have persecuted me, they will also persecute you" and posing the question: "What would Jesus do?"
Mr Liley said: "Lichfield Cathedral is a place of Christian worship and the centre of mission for the Diocese of Lichfield. We are open to all and want everybody to feel welcome here – but people visiting the Cathedral must act in a way which does not damage the cathedral nor the welcome that we are able to offer other visitors.
"The BNP are wrong to suggest that Jesus would vote for the BNP. I don't know who he would vote for, but his parable of the Good Samaritan was a clear example about the value we should place on people from other communities.
"Lichfield Cathedral encourages people to vote in elections and we seek to engage with all legitimate politicians. But we will not endorse any particular candidate or party and it is wrong for any party to seek to use the Cathedral in a way which might imply endorsement, regardless of how much we may support or oppose what they stand for."
A spokesman for the BNP said the activist had only been trying to take a photo with the cathedral in the background, on Tuesday afternoon, to show the places its campaign bus had visited.
He said: "The cathedral is synonymous with Lichfield. It's a very quaint English place so when you depict it, what better thing to show than the cathedral?
"We're about to put our first candidate in Lichfield and I think we're going to get a very big vote. There's a big mosque planned for Lichfield but there's a lot of opposition to it."