England and Wales Cricket Board (ECB) chairman David Morgan had promised Zimbabwe cricket chiefs at a meeting in Harare that England would proceed with the tour in exchange for the Zimbabweans visiting England in 2003 - which they did.
"There is an exchange of letters which I think a lawyer would certainly say is a legally binding commitment," ECB chief executive Tim Lamb told Monday's edition of the 'London Evening Standard'.
"But at the end of the day we have to take all factors into consideration," he added.
In February, England pulled out of a World Cup match in Harare on safety grounds, a decision that prompted Morgan's mission to the Zimbabwean capital.
Under International Cricket Council (ICC) rules matches and tours can only be aborted on safety grounds.
However, following a report published by senior ECB official Des Wilson last week, England are considering withdrawing from the tour for moral reasons following international concerns over the regime of Zimbabwe President Robert Mugabe.
The ECB were due to decide whether to tour at a meeting of their management board on Thursday.
But while that meeting is still going ahead as scheduled, the ECB confirmed that the management board would make its decision at a meeting to be held before the end of February.
Meanwhile England batsman Mark Butcher said that he hoped the decision would be taken out of the players' hands, which was not the case at the World Cup.
"Currently the Government and the ECB are talking and making decisions at a much higher level," Butcher told BBC Sport.
"So with a bit of luck they'll have decided what the right way to go is," added the Surrey left-hander who is due to meet up with his England teammates on February 10 for two weeks of training ahead of the team's West Indies tour.
Butcher was speaking at The Oval where Surrey were announcing a new sponsorship deal worth 1.5 million pounds (2.7 million dollars) over three years.
"You can't poke your head in the sand and say these things don't make any difference to you because you're a sportsman - of course they do. There are moral issues - there were back then - but there are decisions being made at a higher level," Butcher said.
"We're going to the West Indies on February 25 and there are subsequent series in the summer and we're focussed on that."
England could face compensation claims if the tour does not go ahead. But recent official ECB statements have all used the word "postponement" rather than "cancellation", a move that could provide a way out of the looming dispute.
ECB keen to have Government meeting