ng-submit not calling controller function

I am writing a simple form that submits some values to a function in an angularJs controller when the form is submitted. I have done this before with no issues but there seems to be a problem with this particular piece of code as the function does not seem to be being invoked.

I have tried with 'ng-click' on an element in the scope to check the controller was being loaded correctly and this worked fine, so this seems to be an issue with 'ng-submit'.

Here is my code:

View:

       <form name="briefForm" role="form" data-ng-submit="briefOneSubmit($this)" >
                <!-- FIRST NAME -->
                <span class="input-label padding-top"> First Name* </span>

                <label class="item item-input brief-field">

                    <input type="text" ng-model="formData.firstName" name="firstName" required>

                </label>

                <span data-ng-show="briefForm.firstName.$error.required && briefForm.firstName.$dirty" class="help-block">A first name must be entered</span>

                <!-- LAST NAME -->
                <span class="input-label"> Last Name* </span>

                <label class="item item-input brief-field">

                    <input type="text" data-ng-model="formData.lastName" name="lastName" required>

                </label>

                <span data-ng-show="briefForm.lastName.$error.required && briefForm.lastName.$dirty" class="help-block">A last name must be entered</span>

                <!-- COMPANY -->
                <span class="input-label"> Company* </span>

                <label class="item item-input brief-field">

                    <input type="text" data-ng-model="formData.company" name="company" required>

                </label>

                <span data-ng-show="briefForm.company.$error.required && briefForm.company.$dirty" class="help-block">A company must be entered</span>

                <!-- EMAIL -->
                <span class="input-label"> Email Address* </span>

                <label class="item item-input brief-field">

                    <input type="email" data-ng-model="formData.email" name="email" required>

                </label>

                <span data-ng-show="briefForm.email.$error.required && briefForm.email.$dirty" class="help-block">A valid email address must be entered</span>

                <!-- PHONE NUMBER -->
                <span class="input-label"> Phone Number </span>

                <label class="item item-input brief-field">

                    <input type="email">

                </label>

                <!-- TERMS TICK BOX -->
                <div class="terms-section">

                    <span class="terms-text"> I have read and agreed to the </br><a class="terms-link" href="#" ng-click="termsLink()"> Terms and conditions </a> </span>

                </div>

                <!-- SUBMIT BUTTON -->
                <input type="submit" id="submit" class="button button-block button-buy" value="Get Started" />

                <!-- MANDATORY LABEL -->
                <p class="padding-top">* Mandatory fields</p>

            </form>

Controller:

$scope.briefOneSubmit = function(form) {
            console.log(form);
        };

I can't seem to see why this function is not being invoked. Can anyone see why this may be occurring? Thanks