Supermarkets and retailers are running short on stock of bubbly -- as congestion at the ports continues to wreak havoc

Global hold-ups of cargo ships at ports around the world and lengthy unloading delays at Ports of Auckland have been ongoing since October last year.

Vintners' Ric Little says it is constantly backing up.

He says they're now looking at about a 20 week lead time to get product out of Europe, with all the delays, so it's pretty hard.