Key Senate crossbencher David Leyonhjelm said he will continue to support company tax cuts out of respect for Finance Minister Mathias Cormann – but he will not guarantee his support for the government on any other matter after claiming Malcolm Turnbull broke a deal with him over euthanasia.

Senator Leyonhjelm, of the Liberal Democratic Party, frequently votes with the government in the Senate on legislation, making him one of the more dependable crossbenchers.