Phone not validated for numbers

Hi I want to use the Phone field to allow a user to type in their phone number. I am in the UK so I have to use the international type but it allows the user to type in letters.
Can this be changed so it checks for numbers?

It would be great to limit inputs to only accept numerals. For now at least I can accomplish this with jQuery:

jQuery(document).ready(function($) {
	$("#input_id").keydown(function(event) {
		if ( event.keyCode == 46 || event.keyCode == 8 ) {
		}
		else {
			if (event.keyCode < 48 || event.keyCode > 57 ) {
				event.preventDefault();
			}
		}
	});
});

Here is a solution

I hope they will implement it, since it's almost just a c/p job ;)