KATHMANDU: CPN-UML General Secretary Ishwor Pokharel has said implementation of the Constitution was a challenging task ahead. Addressing a programme orgnaised to welcome the newly elected committee of the Trekking Agencies' Association of Nepal (TAAN) at the party office, General Secretary Pokharel said the elements against implementation of the Constitution were rearing their heads. 'With the promulgation of new Constitution, political transition has officially ended, but implementation of the Constitution is still challenging,' he said. He urged the newly elected working committee of the TAAN no to engage in any political interest, but to devote itself to promotion of the country's tourism. Former Minister for Tourism Kripasur Sherpa also urged the TAAN leadership to abide by professional integrity. TAAN Chairman Chandra Prasad Rijal said the TAAN would be taken ahead as an exemplary professional institution.