Cruise ships face the threat of being banned from Venice following a crackdown on water traffic after the death of a German tourist two weeks ago.
The new proposals have been suggested by Italy's environment minister Andrea Orlando.
He told the Italian daily Il Gazettino: “There will always be a margin of risk and even that margin is too high a risk.
“The problem is not just the presence of large ships in St Marks basin but in general the presence of ships in the lagoon.”
He expected a “concrete response that could be translated into immediate action”, as the problem is getting worse all the time, he said.
“The number of cruise ships passing in front of St Marks’s Cathedral has grown by seven per cent this year alone.”
Orlando said he would put the proposals in front of cross party parliamentary committee next month, according to the Daily Mail.
His comments follow the death of Joachim Vogel, 50, a professor of criminal law, who was crushed against a dock by a reversing water bus as he took a tour with his family by gondola near the Rialto Bridge.
The mayor of Venice reportedly wants to see cruise ships dock at Porto Marghera. Other suggestions have included a floating off-shore port.
Alternative solutions would see the number of cruise ships allowed to enter the lagoon severely limited, or the dredging of a new approach to the main cruise passenger terminal but avoiding the channel which passes St Marks Square.
The proposals would essentially put in action emergency legislation drafted after the Costa Concordia tragedy that would prevent ships of more than 500 tonnes coming within two nautical miles of landscapes of value such as the Venice lagoon or fragile environments such as the marine sanctuary between Sardinia and north-east Italy, the newspaper reported.