In light of Buzek's besieged administration, opposition parties took advantage of AWS' organisational and economic weaknesses. From the centre left, a political coalition between the Democratic Left Alliance (SLD) and the Labour Union (UP), headed by Leszek Miller, appeared as the ruling government's most formidable, united and vocal opposition. On the centre right, Solidarity's traditional spectrum of support increasingly became divided by the emergence of new political groups. Civic Platform (PO), composed of former AWS and UW members, repeated calls for a low flat-rate income tax and a culling of bureaucracy to attract investment. Further down the right, the Law and Justice party (PiS), composed of AWS' more conservative and anti-communist adherents, campaigned on promises of tough anti-corruption and organised crime legislation.