how to cancatenate string with increment id in mail template

i want to concatenate a string ‘P’ with the incremend_id variable in .html file of email template without affect the translation , but i don’t know why it didn’t work

i have don this :

<p class="order-number">
                <strong>
                    {{trans 'Order # : %increment_id' increment_id='P'.$order.increment_id |raw}}
                </strong>
            </p>