Complex sentence: The Top Level Group of UK Parliamentarians for Multilateral Nuclear Disarmament and Non-proliferation (TLG) is a cross-party advocacy group in the United Kingdom, whose primary focus is the advancement of the nuclear disarmament and non-proliferation agenda in Britain and internationally.
Split into simpler sentences: The Top Level Group of UK Parliamentarians for Multilateral Nuclear Disarmament and Non-proliferation (TLG) is a cross-party advocacy group in the United Kingdom. Its primary focus is the advancement of the nuclear disarmament and non-proliferation agenda in Britain and internationally.