The residents of Aberfan petitioned George Thomas, who had succeeded Hughes as Secretary of State for Wales in April 1968, for the tips to be removed; they entered the Welsh Office and left a small pile of coal slurry on the table in front of him to make their point; Thomas later stated the tips "constitute a psychological, emotional danger" to the people of Aberfan. The NCB had received a range of estimated costs for removing the tips, from £1.014 million to £3.4 million. Robens informed HM Treasury that the cost would be £3 million, and informed them that the NCB would not pay for the removal; between November 1967 and August he lobbied to avoid having the NCB pay. The Chief Secretary to the Treasury also refused to pay, and said that the costs were too high. Although the government had initially favoured landscaping—an option cheaper than removal—they were eventually persuaded that removal was preferable.