Churchill was furious when he found out, probably through intelligence intercepts of Swedish diplomatic cables. He wrote to Halifax on 26 June complaining of Butler's "odd language", which hinted at a lukewarm or even defeatist attitude. Butler, who was lucky not to be sacked, made a four-page handwritten reply the same day, claiming that he had kept to the official British line and had said "nothing definite or specific that I would wish to withdraw", but offering to resign. On 28 June, after being shown Churchill's letter, Butler wrote to Halifax giving an unconvincing explanation, which he later repeated in his memoirs, that by "common sense not bravado", he had been pushing the official line that there could be no peace until Germany had disgorged her conquests. Jago argues that Butler may have been covering for Halifax. Halifax's biographer, Andrew Roberts believes that Butler had been putting words into Halifax's mouth, and that Halifax had already moved away from his earlier openness to a compromise peace.