when consuming 3rd party api in mvc controller want to return whole response
<p>I am consuming a 3rd party api in an MVC controller, in order to return the json to their javascript endpoint on my site (the short answer as to 'why' is to improve security - they describe this as a 'relay'), in the process I am using WebClient:</p>

<pre><code>public ActionResult relay (string link)
{
    // some code here to insert an access token into their json (on the request's content stream), and reserialise.

    string result = "";

    using (WebClient client = new WebClient)
    {
        client.Headers[HttpRequestHeader.ContentType] = "application/json";

        try
        {
            result = client.UploadString(ApiUrl + link, "POST", jsonParamsFrom3rdpartyJS);
        }
        catch (WebException ex)
        {
            HttpWebResponse _errorResponse = (HttpWebResponse) ex.Response;

            if (errorResponse.StatusCode == HttpStatusCode.PaymentRequired)
            {
                ErrorLogger.WriteToErrorLog("Need to pay the 3rd party");
            }       
        }           
    }

    return Json(result);
}
</code></pre>

<p>Is there any way I can return the whole response from the 3rd party to the javascript? It looks like there is a bit of json with an error message within their response, but can't get it to the javascript which is also expecting to receive the 402 response (this may be being trapped elsewhere?)</p>