As a large part of the Tyrrell budget was provided by Ford , and another significant element came from French state-owned petroleum company Elf , which had an agreement with Renault that precluded supporting a Simca partner , Ken Tyrrell had little alternative but to buy a March 701 chassis as interim solution while developing his own car in secret .
Because of this , Ken Tyrrell had to buy a March 701 chassis as temporary solution while making his own car in secret .