The EU's incoming regional policy and budget chiefs on Tuesday challenged the bloc's six paymasters, who are keen to cap the future budget, saying funds were needed both to boost growth and revive poorer areas. Future regional policy Commissioner Danuta Huebner said the two-pronged spending strategy required sufficient financing from member states following the accession of 10, mostly ex-communist countries to the European Union in May. Dalia Grybauskaite, incoming budget commissioner, backed plans to replace Britain's 4.6 billion euro rebate from EU coffers with a system of refunds for all net payers. "Our biggest challenge is low growth because it undermines our cohesion policies. It weakens our position as a global player," Huebner, Poland's former minister for Europe, said in testimony before the European Parliament. Huebner and Grybauskaite are among 24 members of the Commission taking office on Nov. 1 being grilled this and next week by the EU legislature. They both vowed to defend the 2007-2013 EU budget drafted by the outgoing EU executive in which 336 billion euros ($413.4 billion) are earmarked for regional aid. --more 2302 Local Time 2002 GMT