In several previous Labour manifestos there had been a firm promise to ban hunting. (Here is a site with an archive of all of them, dating back to 1900.)

The 2001 one was more waffly, and said: "The House of Commons elected in 1997 made clear its wish to ban fox-hunting. The House of Lords took a different view (and reform has been blocked). Such issues are rightly a matter for a free vote and we will give the new House of commons an early opportunity to express its view. We will then enable Parliament to reach a conclusion on this issue. If the issue continues to be blocked we will look at how the disagreement can be resolved."

That strikes me as a pretty clear implication that opponents of hunting with dogs could vote Labour in a confident expectation of getting a ban this time.