I inserted an echo statement into the function bda_faqs_load_js which was outputted in the head of the the HTML.
I know it is not working as when I review the HTML source the required ui.core.js and ui.widget.js are not included on the page.
If I explicitly declare a javascript with wp_enqueue_script it works e.g.
function bda_faqs_load_js() {
wp_enqueue_script('jquery');
wp_enqueue_script( 'bda-faqs-jquery-ui', plugins_url().'/bda-faqs/bda_faqs.jquery-ui.js', array('jquery'));
}
But I really wanted to use the built in versions to keep the plugin as light weight as possible.
in a plugin file called bda_faqs.php