If you feel pressured by your travel provider to take the insurance offered by them, Citizens Advice states that they are breaking the law if they try to make you purchase it or charge you more for your holiday should you choose to accept it.
You are not obligated to accept insurance from any provider, and it is important that you are happy with the terms and conditions of the policy. If you feel you are being forced into purchasing travel insurance, refer to the Financial Conduct Authority (FCA) or Financial Ombudsman Service (FOS) for further advice and information.