Overriding Default required_providers

How can I override the required_providers supplied via config/terraform/terraform.tf ?

We have just started using Terraspace and are a predominantly AWS-based customer.
Therefore our config/terraform/terraform.tf supplies the required_providers {} block to all stacks.
We now have a single stack which must include the hashicorp/azurerm provider.

I have considered either:-

  1. Create a new project with the azurerm provider and duplicate much of our existing stuff OR
  2. an expansion within config/terraform/terraform.tf to include a setting which is provided at the stack level

Has this been encountered before ?
Does anyone have any wisdom in this matter ?

I solved this by providing a stack-level terraform.tf which then supercedes the project-level terraform.tf