mPDF Landscape printing in codeigniter - php

Question

I've been trying to print a PDF using mPDF and codeigniter. This PDF as well as all the other ones in the application print fine, but I can't get it to print landscape.
I've tried all the combinations of parameters as suggested in other questions, but none of them has had any effect on the printing. Therefore it has to be something wrong with the way I'm implementing the mPDF library.
My current controller:
$filename = $order_number;
$pdfFilePath = FCPATH."/downloads/orders/$filename.pdf";
$data['page_title'] = 'Order';
if (file_exists($pdfFilePath) == TRUE)
{
unlink($pdfFilePath);
}
if (file_exists($pdfFilePath) == FALSE)
{
ini_set('memory_limit','128M'); // boost the memory limit
$html = $this->load->view('generate_pdf', $data, true); // render the view into HTML
$this->load->library('pdf2');
$pdf2 = $this->pdf2->load();
$pdf2->WriteHTML($html); // write the HTML into the PDF
$pdf2->Output($pdfFilePath, 'F'); // save to file because we can
}
The mPDF library:
<?php if (!defined('BASEPATH')) exit('No direct script access allowed');
class Pdf2 {
function pdf2()
{
$CI = & get_instance();
log_message('Debug', 'mPDF class is loaded.');
}
function load($param=NULL)
{
include_once APPPATH.'/third_party/mpdf/mpdf.php';
if ($params == NULL)
{
$param = '"en-GB-x","A4-L","","",10,10,10,10,6,3';
//$param = '"en-GB-x","A4","","",10,10,10,10,6,3',L;
//$param = '"en-GB","A4-L"';
//$param = '"L"';
//$param = '\'en-GB-x\',\'A4-L\',\'\',\'\',10,10,10,10,6,3,L';
}
//echo $param;
return new mPDF($param);
}
}
Is mPDF ignoring the parameters or do I have it wrong?