Abandonment of a branch main

A method for abandoning a branch main joined to a fluid-carrying spine main, the method comprising the steps of exposing a portion of the branch main in preparation for abandonment, gaining access to the bore of the branch main at an access point and then permanently blocking the bore of the branch main at a blockage point closer to the junction than to the access point by positioning at the blockage point a plug having a sealant which, upon curing, adheres the plug to an internal wall of the branch main, wherein before access is gained, but subsequent to the exposing step, an aperture is made in the wall of the branch main upstream of said access point and the bore of the branch main it temporarily blocked upstream of the access point by introducing a blocking means into the bore of the branch main through the aperture in the wall of the branch main.