Error in powershell script while trying to integrate SOAPUI tests in VSTS

I am using a script in GIT repository in VSTS(Visual Studio Team Services) to execute SOAPUI test. I am using a power shell task in the build definition. Build is getting succeeded but it is not hitting the SOAPUI part.I could see the logs as below:

Start-Process : A positional parameter cannot be found that accepts argument xxxxx.
At line:1 char:1
+ Start-Process -FilePath “C:\Program Files (x86)\Smartbear\SOAPUI\Bin\.. ...
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   + CategoryInfo          : InvalidArgument: ( [Start-Process], ParameterBindingException
   + FullyQualifiedErrorId : PositionalParameterNotFound,Microsoft.PowerShell.Commands.StartProcessCommand

I have already tried to open the soapui path mentioned above from plain powershell and I am able to open it, but same in not working through my script. 

Below is my script:

$testrunner = '.\Program Files\SmartBear\SoapUI-5.4.0\bin\testrunner.bat'
$project = '$(System.DefaultWorkingDirectory)\SOAPUI Project\SOAPUI\xxxx.xml'
$arguments = $project, '"-sTestSuite 1"', '"-RJUnit-Style HTML Report"'

#Start-Process Powershell -FilePath $testrunner -ArgumentList '"$project"' , '"Set-ExecutionPolicy Restricted -Force"' -Verb RunAs
Start-Process "powershell" -FilePath '.\Program Files\SmartBear\SoapUI-5.4.0\bin\testrunner.bat' -Verb runAs
#start-process $(System.DefaultWorkingDirectory)\SOAPUI Project\SOAPUI\XYZ.xml
if ($exitWithError -eq "true")
{
Write-Host "Build task failed"
exit 1
}
else
{
Write-Host "Build task pratap"
exit 0
}

Can anyone suggest the changes I should do get the desired result.

Regards,

Pratap