You can always use the 'pre' tag inside the label, and just enter the blank spaces in it, So you can always add the same or different number of spaces you require
<form>
<label>First Name :<pre>Here just enter number of spaces you want to use(I mean using spacebar to enter blank spaces)</pre>
<input type="text"></label>
<label>Last Name :<pre>Now Enter enter number of spaces to match above number of
spaces</pre>
<input type="text"></label>
</form>
Hope you like my answer, It's a simple and efficient hack