How to make tinymce paste in plain text by default

For the tinyMCE 3X or 4X things have change a little.now you can do this and it works fine.

tinymce.init({    plugins: "paste",    paste_as_text: true});

I have solved this problem with this code

tinyMCE.init({...plugins : "paste",paste_text_sticky : true,setup : function(ed) {    ed.onInit.add(function(ed) {      ed.pasteAsPlainText = true;    });  }....})

EDIT: this solution is for version 3.x, for 4.x version read the answer from @Paulo Neves

The problem is that Paste plugin automatically resets plain text paste on every paste. So all we need to do - set it back. The following code should help.

tinyMCE.init({...oninit : "setPlainText",plugins : "paste"....});

The definition of setPlainText

 function setPlainText() {        var ed = tinyMCE.get('elm1');        ed.pasteAsPlainText = true;          //adding handlers crossbrowser        if (tinymce.isOpera || /Firefox\/2/.test(navigator.userAgent)) {            ed.onKeyDown.add(function (ed, e) {                if (((tinymce.isMac ? e.metaKey : e.ctrlKey) && e.keyCode == 86) || (e.shiftKey && e.keyCode == 45))                    ed.pasteAsPlainText = true;            });        } else {                        ed.onPaste.addToTop(function (ed, e) {                ed.pasteAsPlainText = true;            });        }    }

So now it always will be plain.