Background: Frederik Willem de Klerk DMS (Afrikaans pronunciation: ['frI@d@r@k 'v@l@m d@ 'klerk]; born 18 March 1936) is a South African politician who served as State President of South Africa from 1989 to 1994 and as Deputy President from 1994 to 1996. South Africa's last head of state from the era of white-minority rule, his government focused on dismantling the apartheid system and introducing universal suffrage.
Context: De Klerk had been unhappy that changes had been made to the inauguration ceremony, rendering it multi-religious rather than reflecting the newly elected leader's particular denomination. When he was being sworn in, and the chief justice said "So help me God", de Klerk did not repeat this, instead stating, in Afrikaans: "So help me the triune God, Father, Son, and Holy Spirit".  Mandela reappointed de Klerk's finance minister, Derek Keys, and retained Chris Stals, a former member of the Broederbond, as the head of the Central Bank. De Klerk supported the coalition's economic policies, stating that it "accepted a broad framework of responsible economic policies".  De Klerk's working relationship with Mandela was often strained, with the former finding it difficult adjusting to the fact that he was no longer president. De Klerk also felt that Mandela deliberately humiliated him, while Mandela found de Klerk to be needlessly provocative in cabinet. One dispute occurred in September 1995, after Mandela gave a Johannesburg speech criticising the National Party. Angered, de Klerk avoided Mandela until the latter requested they meet; when they ran into each other, they publicly argued in the street. Mandela later expressed regret for their disagreement but did not apologise for his original comments. De Klerk was also having problems from within his own party, some of whose members claimed that he was neglecting the party while in the government.  Many in the National Party--including many members of its executive committee--were unhappy with the other parties agreed upon a new constitution in May 1996. The party had wanted the constitution to guarantee that it would be represented in the government until 2004, although it did not do this. On 9 May, de Klerk announced that the National Party would withdraw from the coalition government. The decision shocked several of his six fellow Afrikaner cabinet colleagues; Pik Botha, for example, was left without a job as a result. Roelf Meyer reported feeling betrayed by de Klerk's act, while Leon Wessels thought that de Klerk had not tried hard enough to make the coalition work. De Klerk announced that he would lead the National Party in vigorous opposition to Mandela's government, stating that he wanted to ensure "a proper multi-party democracy, without which there may be a danger of South Africa lapsing into the African pattern of one-party states".
Question: Did anybody else have a strained relationship with him?

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