No. No. No no no no no. You lose syntax highlighting and error correction in basically every editor that I can think of. Trying to manage real-world application templates as multi-line javascript strings (that quickly balloon into hundreds of lines) is an absolute nightmare. Save yourself the headache and make a <script> tag with an id, and type=text/html (or x-jquery-tmpl, if you're using the templating features built-in to jQuery).
Fetch the element using whatever, grab its innerHtml, and pass that string along to the templating library of your choice. The browser doesn't render the initial template markup because it's in a script tag, and it doesn't interpret it as javascript because of the non-standard type attribute. So for all intents and purposes it completely ignores it, but it's fully accessible for your use. Win-win.