No, it is very unlikely that the ban will be reconsidered, let alone lifted. There is some pressure for lighter regulation, from serious match shooting enthusiasts for example. For a host of reasons 'military style weapons', let alone semi-autos, were never licensed in large numbers. It has become increasingly hard to legally possess a handgun - it has been illegal since 1997 - and 'home defence' has never been accepted as a rationale.
The legislative 'crack down', mainly using greater regulation, came after four mass shootings:
Hungerford 1987, sixteen dead, wounded fifteen, using a military semi-auto SKS and other weapons:http://en.wikipedia.org/wiki/Hungerford_massacre
Monkseaton 1989, one dead, sixteen shot, with a shotgun:http://en.wikipedia.org/wiki/Monkseaton_shootings
Dunblane 1996, sixteen children and one adult dead, using licensed hand guns:http://en.wikipedia.org/wiki/Dunblane_massacre
Cumbria 2010, twelve dead, with eleven injured, using a shotgun and .22 rifle:http://en.wikipedia.org/wiki/Cumbria_shootings
We still have regular home hostage incidents, armed crime - mainly with illegal handguns; it is rare to have multiple shooter incidents - in fact I cannot readily recall one. The one I can was long ago, the 1911 Sidney Street siege, involving Russian anarchists, with automatic weapons, three policemen and a firefighter murdered:http://en.wikipedia.org/wiki/Siege_of_Sidney_Street