As stated in the scenario, the changes that Jessica and John wish to make are prohibited by the articles of association. Therefore, the directors must seek the shareholders' approval to amend the articles. Directors cannot override the provisions set out in the articles. A change in the articles of a company requires a special resolution, which mandates a minimum of 75% of the shareholders' votes. 

Key Point: According to the Companies Act 2006, any amendments to a company's articles of association require a special resolution passed by at least 75% of the shareholders' votes. This ensures that significant changes to the company's governance framework receive substantial shareholder support, thereby protecting the interests of minority shareholders and maintaining a balanced approach to corporate governance.